Mollusca from Kaawa Creek Beds, West Coast, South of Waikato River.
[Read before the Auckland Institute, 4th October, 1927; received by Editor, 8th January, 1988; issued separately, May 24th, 1928.]
In 1919 one of the present authors described a new fossiliferous Tertiary horizon at Kaawa Creek (Bartrum, 1919, a),* publishing a list of mollusca based on determinations by the late Mr. A. Suter. At the same time he published descriptions of several new species determined as such for him by Mr. Suter (Bartrum, 1919, b). The original material was limited to that obtainable from two or three small blocks fallen from an inaccessible spot in the sea-cliffs about 50ft. above beach level. During recent years, however, a large slip has afforded a splendid opportunity for collecting, and Bartrum has been able to make further collections during short periods available when on field excursions with students. He is greatly indebted to several of these students for their assistance, especially as a new species described in this paper was collected by one of them—Mr. F. J. Turner—in 1924. He further wishes to thank Mr. Powell for kindly collaborating in this paper and bringing to its preparation his surprising knowledge of modern molluscs and the resources of his extensive collections.
Both authors owe much to Dr. J. Marwick, who has kindly lent types for comparison and has examined one or two new species of doubtful generic position, as well as furnishing critical notes upon the original collection.
Revision of List of Kaawa Mollusca.
The original list of mollusca from Kaawa Creek (Bartrum, 1919, a) has been revised by Dr. Marwick after examination of collections made by the New Zealand Geological Survey as well as of that of Bartrum, and the revised list was published by Henderson and Grange (1926). Recent collecting, however, has added new records, whilst many nomenclatural changes have been introduced during recent revision of various genera, so that a fresh list of the mollusca so far found in the Kaawa beds is appended. This could be greatly extended by systematic collecting, which has not yet been attempted.
Description of New Species and General Remarks.
Unless stated to the contrary, the shells described or discussed have been collected by J. A. Bartrum and are in the Auckland University College Collection.
[Footnote] * See list of literature for reference in this and similar cases.
Emarginula striatula Q. and G.
The Kaawa shells are slightly narrower than the Recent species, which they otherwise resemble closely.
Montfortula kaawaensis (Bartrum.).
Finlay (Trails. N.Z. Inst., vol. 57, 1926, p. 344) refers Tugali kaawaensis Bartrum to the genus Montfortula.
Tugali opuraensis n. sp. (Fig. 20).
The shells listed as Tugali bascauda Hedley and T. intermedia (Reeve) by Bartruam (1919, a) prove to belong to the same species, which is described, on the basis of fresh material, as a new species allied to the Recent T. elegans Gray (= T. intermedia)—(see Finlay, loc. cit. pp. 344-5).
The sculpture is the same as that of the Recent species, the trifurcation of the central rib from the nucleus being especially well shewn in a small paratype (6.4 mm. × 3.9 mm. × 1.9 mm.). The apex is, however, nearer the anterior end, its distance from this latter being one-eleventh of the length of the shell in the holotype and one-sixth in the paratype, whilst in T. elegans Gray this ratio varies in different specimens examined from one-fourth to one-fifth approximately.
Dimensions of holotype: 11 mm. × 6 mm. × 2.4 mm.
Trochus bibaphus n. sp. (Figs. 21 and 22).
This species is represented by a solitary shell which was collected by Mr. F. J. Turner in 1924.
Its tall conical shape appears to indicate that it is the direct ancestor of T. huttoni (Cossmann) (see. Finlay, loc. cit., p. 349) Though its spire angle is close to that of this latter shell, its suture is abutting and the peripheral margin, of its base sharper.
General sculpture consists of low, flat, smooth cinguli alternating with fine threads on spire-whorls. Oblique growth-lines fairly prominent. On the base 13 cinguli without intervening threads. On the antepenultimate whorl 9 primary cinguli, whilst both T. tiaratus Q. and G. and T. huttoni (Cossman) have 5. Protoconch slightly worn. Colour (still preserved) pink, faintly cheeked by small elongated rectangular splashes of white carried at regular intervals on the cinguli.
Dimensions of holotype: Height, 9.2 mm.; width, 10.7 mm.
Spectamen cf. egena (Gould).
Finlay (loc. cit., pp. 358-360)has discussed the genus Monilea Swainson, 1840, and, anticipating distinctive radular characters, has introduced a new generic name Antisolarium for the species M. egena (Gould), which Powell (Rec. Cant. Mus., vol. 3, pt. 1, 1926, p. 45) has included in the genus Spectamen. This forecast of radular differences, however correct it may ultimately prove, scarcely justifies the rejection of Spectamen. If carried to a logical conclusion, such procedure would prohibit all provisional generic allocations based only on shell characters and would thus undesirably and unnecessarily multiply generic names.
The Kaawa shell represents a new species ancestral to S. egena (Gould), but is too poorly preserved to be worth specific description.
Elachorbis cingulatus (Bartrum).
This name replaces Circulus cingulatus (Bartram) of the early list of Bartrum (1919, a). See Iredale, 1915, p. 444.
“Turbo” postulates Bartrum (Figs. 6 and 7).
Bartrum (1919, b, p. 100) described under the above name a shell, identified by the late Mr. A. Suter as a Turbo, which was represented only by a basal fragment. Recent collecting has added over twenty specimens in varied states of preservation. The shell material is very thin and fragile, so that it proved impossible to collect any specimen with the apex at all well preserved.
As better material is now available, a neotype has been selected for description. The species does not appear to be strictly a Turbo, for it differs from most shells placed in that genus in the extreme thinness of the shell-material, in the imperfect glaze on the parietal wall, generally allowing continuation of the sculpture on the inner lip, and in the discontinuous peristome. The columella is very strongly developed.
The shell shews affinities with Tonna, but discordant features are the rather straight columella and the apparent absence of the basal siphonal notch, which may, however, be represented by slight sinuosity near the base. It is, further, much smaller than known New Zealand species of Tonna.
For these reasons it has been considered preferable to leave this species provisionally in the genus Turbo, in the absence of anymore suitable generic position.
The neotype selected is 31.5 mm. high and 31.8 ram, broad. It possesses 4 rounded spiral ribs on the penultimate and 11 similar ones on the body-whorl.
Kaawatina gen. nov.
Type: Kaawatina turneri n. sp. (Figs. 65 and 66).
This new genus is based on two tiny shells shewing superficial resemblance to Brookula and Rissoa. Its relationships possibly are with the latter genus. Both specimens belong to the same species, and the heavy nature of their shells suggests that they are adults.
The type is the smaller of the two (1.6 mm. × 1-2 mm.) and shews a remnant of the nucleus, whilst the paratype (width 1.5 mm.), which has a broken spire, shews spiral ornamentation not visible-in the holotype.
Shell pyriform, solid, with 3 very rapidly increasing whorls. Spire conical, a little shorter than aperture; outline of whorls fairly sharply convex. Aperture broadly ovate-pyriform; peristome entire-and continuous, separated from parietal wall by a shallow crescentic groove. Outer lip rounded, heavy. Inner lip oblique, slightly arcuate. Elongated umbilical chink.
Uppermost whorl worn and broken, but apparently smooth; its-shape suggests that it probably was not part of protoconch. Two lower whorls are crossed by axial costae (10 on body whorl) oblique to the right at an angle of about 45° and very heavy and blunt, giving shell a corrugated effect. Interspaces of costae on paratype-shew strong regularly-spaced spiral ribs, 10 in number at the outer-
lip, which pass from axial to axial, though -without surmounting them, and also produce a corrugated effect.
The genotype is named after Mr. P. J. Turner, of Otago University.
Melanopsis trifasciata Gray.
Finlay (loc. cit., p. 380) has noted that Neozelanic shells of this genus differ from the European form on which the genus Melanopsis was founded, and has proposed Zemelanopsis n. gen. to replace this latter for New Zealand shells. It is regrettable that no criteria are set forth whereby this proposed genus can be separated from European forms, especially in view of the occurrence of related species in the mid-Pacific (New Caledonia) at the present time.
It is considered preferable to retain the earlier generic name until this omission is rectified.
Turritella cf. Huttoni Cossman.
Marwick (MS.) notes the divergence of the Turritella previously listed as T. huttoni Cossm. (Bartrum, 1919, a) from that species, and remarks that it is undesirable to institute new species until a revision of the group has been effected. The Kaawa specimen, in any case, is too imperfect to serve as the sound basis of a new species.
Struthiolaria arthritica n. sp. (Figs. 55 and 56).
This species is related to S. callosa Marwick (Trans. N.Z. Inst., vol. 55, 1924, pp. 182-3), and is represented by fairly numerous specimens in various stages of growth at Kaawa Creek. It differs from callosa in the feeble development of lower row of nodules on body-whorl, and in its broader, less definite spread of callus on parietal wall and inner lip, without the defined margin or abrupt edge shewn by callosa.
Shell fairly large, oval, with spire about height of aperture. Spire-whorls broadly angular, with a keel at middle. Body-whorl bi-angulate, with lower angle rather poorly developed and carrying occasional swellings which indicate obsolete earlier tubercles. About 8 or 9 strong tubercles on keel of body and antepenultimate whorls.
Spiral sculpture of fine regularly-spaced threads which are a little fainter on body-whorl than on spire. Aperture as in S. callosa, but callus is less thickly spread on inner lip, though it there forms a thick round pad about the middle and also a rounded knob reaching from posterior siphonal notch to a little above the angle, with a slight channel against the somewhat flat shoulder. Protoconch incomplete. Dimensions of holotype (apex missing); Height, 56.5 mm.; breadth, 44 mm.
Struthiolaria pseudovermis n. sp. (Figs. 63 and 64).
Represented by a single fairly small specimen. Solid ovate shell of the vermis group, closely resembling S. vermis itself and S. nana Marwick (Trans. N.Z. Inst., vol. 56, 1926, p. 318) in form, but differing in detail of ornamentation.
Spire-whorls obtusely angled, becoming more eon vex towards apex; a keel on the angle, bearing traces of faintly-developed close-spaced small nodules, which grow progressively stronger until they
are quite prominent on body-whorl as outer lip is approached, though absent on lower rounded keel of this latter whorl.
Suture abutting; not broadly and deeply excavated as in vermis. Shoulder of whorls very slightly convex to flat on upper whorls, but becoming slightly concave on lower whorls owing to development of the tubercles at the angle.
Peripheral area of body-whorl slightly concave owing to absence of middle spiral carina characteristic of vermis.
Spiral sculpture: lirae rather faint on whorls, but stronger on base, which has about 6 irregularly-spaced threads. Aperture, columella and outer lip as in S. nana, though the callus of inner lip, whilst thin on parietal wall, thickens near posterior siphonal notch and spreads to half-way between keels of body-whorl. Protoconch absent.
Dimensions of holotype: Height, 40 mm.; breadth, 25.5 mm.
Struthiolaria illepida n. sp. (Fig. 62).
A large rather thin shell, elongate-oval in form, resembling S. papulosa (Martyn) but proportionately taller, whilst its tubercles are more distant, there being 11 per whorl in the new species compared with 13 to 18 in papulosa. Spire turretted, tall, nearly 1½ times the length of the aperture; spire-whorls strongly angled about the middle with prominent nodular keel and slightly concave shoulder.
Body-whorl has also lower rounded keel proceeding from just above suture, but without tubercles. Peripheral space between keels concave; this space is nearly flat in papulosa, for lower keel is poorly developed. Spiral sculpture of regular lirae, fairly strong on spire-whorls, but fainter on body-whorl, except on base.
Aperture incomplete; outer lip broken away. Columella concave, the beak bent to the right and slightly advanced. Callus of inner lip very thinly though broadly spread; extends as a thin smear to upper nodular keel. Protoconch absent. Holotype (the only specimen) incomplete; 61.5 mm. high.
Neojanacus kaawaensis n. sp. (Figs. 16, 17, 18, 19).
Though the shells included here shew certain important variation from the genotype of Neojanacus, they are provisionally included in that genus for want of a better allocation. The chief points of divergence are the slight displacement of the apex from its terminal position in the Recent species, and the development, on the posterior lower surface, of a ridge which simulates the early stage of development of the basal plate of Crypto, (= Crepidula).* This is especially the case in juvenile, but less so in more mature forms.
In the new species the holotype which is judged to be a relatively mature shell, is a flattened very slightly elevated shell quadrate in outline, though the juvenile paratype is rounder and more convex. The apex is near, hut not at, the posterior margin and consists of about 1½ spirally-coiled smooth whorls.
Shell smooth, with faint concentric lamellar imbrication towards margins. Muscle-scars indistinct, but apparently horse-shoe shaped, open towards the front.
[Footnote] * This appears also in juvenile shells of the Recent species of Neojanacus.
Dimensions of holotype (Figs. 16 and 17): Length, 6 mm.; breadth, 6.7 mm.; diameter of paratype, 3.2 mm.
Hipponyx sp. (Fig. 33).
Powell (N.Z. Journ. Sc. and Tech., vol. 6, 1924, p. 284) shews, that the shell recorded by Bartrum (1919, a) is not antiquatus, but a separate species.
Until better material than the present solitary specimen is available, however, it is undesirable to describe the shell as a new species.
Zegalerus crater Finlay.
The species recorded by Bartrum (1919, a) as Calyptraea maculata (Q. and G.) proves to be identical with that described by Hutton as Trochita alta. Finlay (Trans. N.Z. Inst., vol. 57, 1926, pp. 391-2) discusses New Zealand calyptræids, referring several types to the genus Sigapatella. Others, however, with which Trochita alta is provisionally included, are referred by Finlay to a new genus Zegalerus. Radular characters (presumably determined by Finlay) separate this genus from Sigapatella and ally it to Galerus Humphrey (= Calyptraea Lamarck, 1799), from which, however, it is distinguished by conchological differences, which are not, however, specified by Finlay.
The specific name alta proves to be preoccupied, so that the shell Trochita alta Hutton now becomes Zegalerus crater Finlay (loc. cit., p. 392).
Finlay (Trans N.Z. Inst., vol. 57, 1926, p. 393) shews that the genus name Crypta has priority over Crepidula, and, apparently on the basis of anticipated differences in the radulae of New Zealand shells from those of crepidulids of other areas, creates a new genus Maoricrypta.
The new name may well wait substantiation by further work and in the meantime the generic name Crypta be used.
Crypta turnialis n. sp. (Figs. 23 and 24).
The crepidulids from the Kaawa beds recorded previously by Marwick (N.Z. Geol. Surv. Bull. No. 28, 1926, p. 57) as Crepidula wilckensi Finlay (replacing C. incurva Zittel) and by Bartrum (1919, a) as C. monoxyla (Less.) and C. gregaria Sow. prove to belong to the one species which is now determined as new.
This new species approaches Crypta wilckensi (Finlay) very closely but differs in having a smoother surface, and in the beak. This latter is narrower, less inflated, less strongly incurved and less distant from the shell margin than in wilckensi, whilst it is oblique towards the anterior margin. This is noticeable even on specimens which have been on a flat surface, and very distinct on those from such locations as the columella of a large gasteropod. Septum somewhat concave, its free margin entire, straight near middle and curving at sides.
Dimensions of holotype: Length, 31.5 mm.; breadth, 19.25 mm., thickness, 11.6 mm. Paratype: 31.5 mm × 12.0 mm. × 11.6 mm.
Crypta opuraensis n. sp. (Fig. 25).
This species is a narrowly arched oval-elongate crepidulid closely-approaching C. densistriata (Suter) but coarser in ribbing. Beak slightly incurved; strongly twisted anteriorly. Septum nearly flat, its free margin apparently entire and only slightly curved. Sculpture of radial ribs, causing undulation of concentric growth-lines, 17 on posterior half; on anterior half a wide dorsal space with ribs only indistinctly shewn, then 5 strong ribs on ventral portion of anterior slope near the beak. Protoconch smooth, strongly incurved. Dimensions (approximate): Length, 25 mm.; width, 15 mm.; thickness, 9 mm. Holotype imperfect.
This is the shell recorded by Bartrum (1919, a) as Crepidula striata (Hutt.).
Finlay (Trans. N.Z. Inst., vol. 57, 1926, p. 394) has shewn that the generic name Cochlis must replace Natica for New Zealand shells, whilst Marwick (Trams. N.Z. Inst., vol. 55, 1924, pp. 545-579), in a revision of the Naticidae of New Zealand, has followed Hedley (Rec. Austr. Mus., vol. 14, No. 3, 1924, p. 154) in replacing the generic name Polinices by Tiber.
The Kaawa Naticidae include:—
Cochlis notocenica (Finlay), (see Finlay, Trans. N. Z. Inst., vol. 57, 1926, p. 394) which in part replaces Bartrum's (1919, a) record of Natica zelandica Q. and G. This species has previously been recorded only from the Oamaruian, but the Kaawa specimens are indistinguishable from topotypes from Awamoa.
Cochlis cf. haweraensis (Marwick). This is apparently a new species represented by one of two shells identified by Suter for Bartrum as N. zelandica Q. and G. It is, however, too imperfect to warrant description.
Uber kaawaensis Marwick.
Uber propeovatus Marwick. This species is very abundant at Kaawa Creek. Here also should be included the earlier record of Polinices sagenus Suter and probably P. amphialus (Watson), though the shell on which this determination was based by Suter is rather too imperfect for exact determination.
Xenophalium kaawaensis n. sp. (Figs. 53 and 54).
Iredale (Rec. Austr. Mus., vol 15, No. 5, Ap. 6, 1927, pp. 333 and 339) introduces the genus names Xenophalium, (p. 333) and Xenogalea (p. 339) for certain Australian helmet shells, but Powell in a paper in preparation shews that the two proposed genera are synonymous, so that Xenophalium takes page priority over Xenogalea.
The Kaawa species referred to this genus appears to be ancestral to the Waipipi representative of the pyrum line—Phalium fibratum Marshall and Murdoch (Trans. N.Z. Inst., vol. 52, 1920, p. 131)—whilst Phalium grangei Marwick (Trans. N.Z. Inst., vol. 56, 1926, p. 319) in its turn is a forerunner of the Kaawa species.
Finlay (Trans. N.Z. Inst., vol. 56, 1926, pp. 230-31), includes grangei in his new genus Euspinacassis, but the fasciole of this species is sculptured transversely, as in pyrum, and lacks the longitudinal sculpture of Euspinacassis, true Phalium and Semicassis. For this reason Phalium grangei Marwick should be relegated to Xenopkalium. Description of Kaawa species:
Large inflated shell, with low conical spire, closely resembling ×. grangei (Marwick).
Earlier spiral-whorls almost flat in outline, later ones slightly convex; body-whorl slightly concave above the broadly-rounded nodular shoulder-angle, but below this, swollen above and rapidly contracting towards base.
Suture bordered below by a low spiral fold with three strong spiral threads beneath on shoulder. Fasciole and outer lip broken away. Inner lip has expanded callus extending to the nodular shoulder-angle of body-whorl, thin on parietal wall but thicker below and practically closing false umbilicus. Columella callus smooth and fairly thick near base. Columella has 2 oblique folds near base, not 1 as in grangei.
Ornamentation differs from that of grangei by having two strong nodular cinguli and an inconspicuous third on body-whorl, in place of three and an inconspicuous fourth, whilst intermediate sculpture is very much stronger. Spire shews only one nodular spiral us in grangei. Between each pair of nodular cinguli, there are two smaller similar bands separated by shallow narrow interspaces. Below the lowest, or third, nodular cingulus there are 13 similar rounded spiral ribs separated by narrow grooves. Protoconch worn.
Dimensions of holotype: Height, 67 mm.; breadth, 48 mm.
Genus Odostomia Fleming, 1813.
Several damaged specimens were collected representing two species of this genus, one being illustrated in Fig. 32. A single specimen agrees closely with Suter's description of O. sherriffi Hutton (N.Z. Geol. Surv. Pal. Bull., No. 3, 1915, pp. 16-17), except that the peripheral spiral sulcus is absent, perhaps as a consequence of wear.
Verconella koruahinensis n. sp. (Figs. 59 and 60).
Species of moderate size near V. adusta (Phil.). Only one specimen known. Fairly large, fusiform shell, with conical spire half the height of aperture and canal. Body-whorl with rounded shoulder-angle bearing rather distant rounded nodules present also on spire-whorls. Nodules regularly increasing and almost spinose on body-whorl; without the connecting carina present in adusta. Axial costae only faintly developed.
Aperture, columella, inner lip, and anterior canal as in adusta; columella broken below. Outer lip thin, not crenulate as in adusta, owing to finer sculpture. Posterior canal narrow, as shoulder of body-whorl is appressed towards suture. Suture appressed, somewhat deep; undulating on account of position immediately below nodular carina.
Ornamentation of numerous spiral lirae (very much finer than in adusta) with intervening still finer secondary threads, varying in number from 1 to 5—generally 1 on spire whorls and 4 or 5 on body-whorl.
Dimensions of holotype: Height (apex broken), 71.4 mm.; approximate breadth, 36.5 mm.
Genus Austrofusus Kobelt, 1879.
Finlay (Trans. N.Z. Inst., vol. 56, 1926, pp. 232-3) shews that the generic name Austrofusus replaces Aethocola Iredale, and also institutes a new genus Zelandiella, based on Neptunea nodosa Hutton as type, in which he includes, amongst other species, the Kaawa shell Siphonalia propenodosa Bartrum. Considerable diagnostic importance is placed by Finlay on the characters of the protoconch.
Examination of reasonably well preserved protoconchs in 8 or 9 specimens of propenodosa fails, however, to bear out Finlay's classification. One apical specimen, in particular, quite indistinguishable in sculpture from propenodosa, shews a conic protoeonch like that of Austrofusus glans (Bolten). (See Finlay, Trans. N.Z. Inst., vol. 56, 1926, p. 232), as is illustrated by Fig. 67.
For this reason, the present writers prefer to relegate propenodosa to the genus Austrofusus. Regarding the shells described as Siphonalia kaawaensis by Bartrum (1919, b), both Marwick (MS.) and Finlay (Trans. N.Z. Inst., vol. 56, 1926, p. 233) have regarded these as identical with propenodosa; further collecting has substantiated this view.
Concerning the sub-genera of Austrofusus, it may be remarked that there is very unequal development of the fascioles of specimens of A. glans (Bolten) from Kai Iwi, some being even imbricating and possessing a slight keel. Further, a Recent A. glans colony from Opotiki shews variable twisting of the pillar and some inequality of development of the fasciole; in one or two specimens it is well developed.
In the sections Neocola and Nassicola, however, the differences of length of the canal are so marked as to be very useful criteria.
Austrofusus (Neocola) ngatuturaensis n. sp. (Figs. 57 and 58).
This species resembles A. taitae (Marwick) and also shews possible alliance to A. gamma Finlay.
Shell moderately small, fusiform with conical spire stepped on account of strongly angled whorls and a little less in height than aperture and canal. Six or seven whorls with high, fairly smooth protoconch (about 3½ whorls) shewn moderately well on paratype. Whorls concave on shoulder, with suture margined by 2 close-spaced strong cords on narrow raised shoulder, and corrugated as result of strong axial costae. Costae faint on excavated shoulder and raised into sharp tubercles on angle, though dying away gradually on base. Earliest spire-whorls convex, later ones have angle-keel about middle. Body-whorl also with faintly nodular lower keel giving more definite bi-angular outline than in taitae.
Aperture oval, oblique, narrowly notched above on account of appressed shoulder, and angled about middle. Outer lip thin and
with strong transverse lirae within. Inner lip thin and narrowly limited. Columella has greater twist to left and back than in typical Austrofusus with very narrow and only slightly raised marginal keels to fascicle.
Spiral ornamentation of strong approximately equidistant, sharply-raised lirae surmounting the costae and their nodular extensions, and generally with 1, sometimes 2, or, on the base, even more, subsidiary threads in the interspaces. Two close-spaced lirae, with a fairly strong intermediate secondary, make a distinct keel at the shoulder-angle, whilst the lower keel of the body-whorl has a single strong spiral rib.
The central basal area has 3 or 4 strong spiral cords, with the usual intervening secondary threads, and is inclined to be finely nodular. Below these there is similar, but less prominent spiral sculpture. Oblique growth-lines may produce a faint reticulation with the spiral lirae.
Dimensions of holotype (incomplete): 24 mm. × 14.8 mm. Paratype: 23 mm. × 13 mm.
Cominella facinerosa n. sp. (Figs. 26 and 27).
Strongly inflated, fusiform shell with conical spire about half the height of aperture and canal. Worn and imperfect; apex and much detail of spire-whorls missing. Body-whorl broadly convex in outline; swollen above and rapidly contracting towards a broad fasciole at the neck. Shoulder conforming with slope of spire; lower margin defined by uppermost of narrow rounded spiral cinguli prominent on body-whorl. Aperture oval, oblique, channelled narrowly above and produced below into a broad short anterior canal bent distinctly to left and back, and moderately deeply notched.
Inner lip appears to be narrowly and lightly calloused above but callus is thickened upon the sinuous columella, and here forms a, plate which gradually tapers to a sharp beak below, and covers a tiny false umbilicus wedged in against the fasciole.
Sculpture spiral; worn from spire. Shoulder of body-whorl appears to have been almost smooth; below this 12 fairly strong equidistant, rounded cinguli, separated by shallow grooves equal in width to the cinguli. Occasional abnormally developed growth-lines-produce irregular local minor lamellation.
Dimensions of holotype: Height, 29 mm.; width, 20.5 mm.
Alcithoe propearabicula n. sp. (Fig. 61).
A small elongate-oval solid volutid with height of conical spire-(broken) about half that of aperture. Whorls with fairly numerous faint axial ribs; 13 to 15 on penultimate whorl and 10 on body-whorl. Whorls very obtusely angled the angle of spire-whorls near lower suture. Axial costae nodular at angle and extending from suture to suture in spire-whorls; gradually diminish on body-whorl until become almost obsolete near outer lip. Body-whorl tapers gradually from angle to neck, where remains of fasciole are imperfectly visible.
Aperture oblique, broad. Outer lip broken below, reflexed and thickened at margin; upper portion locally envelops the angle-nodules, extending to middle of shoulder, and forms a massive broadly-rounded projecting shoulder which encloses a wide, elongated
posterior canal. Inner lip very thinly but broadly smeared with callus, which thickens below and tapers to a point. Columella straight above and with 4 strong wide-spaced oblique plaits, but twisted slightly to left and back at the beak.
Differs from arabicula in more numerous costae on spire-whorls and lower position of the angle of these whorls.
Dimensions of holotype (incomplete): Height, 32.8 mm.; width, 17.8 mm.
Baryspira cf. hebera (Hutton).
Kaawa specimens resemble hebera, though they were not compared with a series of topotypes (Awamoa).
Baryspira exsputa n. sp. (Figs. 28 and 29).
This new species contains the shells previously recorded from the Kaawa beds by Bartrum (1919, a) as Ancilla novae-zelandiae (Sow.), though Marwick (see Henderson and Grange, N.Z. Geol. Surv. Bull. No. 28, 1926, p. 57) has realized the possibility of their representing a new species.
The Kaawa species is relatively small but is otherwise so closely similar to novae-zelandiae that a record of divergent characters will suffice. The essential difference lies in the shorter spire and more inflated body-whorl. In addition, the basal grooves are higher up in the new species.
Dimensions of holotype: Height, 5.7 mm.; breadth, 2.8 mm.
Marginella hesterna n. sp. (Figs. 30 and 31).
The Kaawa species of Marginella approach closely to the Recent New Zealand pygmaea, but differ in the smaller average adult size, the blunter nature of the spire and the very much thicker outer lip.
It is probable, in any case, that true pygmaea is not represented in New Zealand. The type appears to be from Brisbane, for Tomlin remarks (Proc. Mal. Soc., vol. 12, 1917, p. 293) that ' … the type is the larger of two on one tablet; the smaller is labelled “Brisbane M.C.” ', and Australian shells appear to be narrower and more cylindrical than New Zealand ones.
The Kaawa shells average about 4.5 mm. in height, whilst a series of Recent “pygmaea” specimens from Whangaroa average 7 mm., though Suter (Manual, p. 465) records the height of shells from Foveaux Strait as 5.5 mm.
The Kaawa species is a small, very solid, smooth volutiform shell with a low blunt spire one-fifth the height of aperture. Protoconch low, smooth, about 1½ whorls, followed by 3½ convex whorls, the last, or body-whorl, much inflated with a broad convex shoulder, and then tapering fairly rapidly to the base. Aperture long, fairly straight and slightly oblique; wedge-shaped, channelled and narrow above but widening below. A broad shallow anterior notch at base, but without resulting fasciole. Outer lip greatly thickened, slightly reflexed; continues as a sharp ridge or varix across base just above notch. Columella straight and slightly oblique to the left; carries 4 strong, sharp, equidistant plaits near the base, the upper two nearly transverse, the lower pair more oblique. Inner lip polished and ill-defined.
Dimensions of holotype: Height, 4.5 mm.; width, 2.8 mm.
Marginella (?) harrisi Cossm.
The record of M. (?) harrisi Cossm. (Bartrum, 1919, a) is incorrect, for the shell on which it was based is probably an imperfect specimen of the new species.
Genus Austrodrillia Hedley, 1918.
Hedley (Rec. Aust. Mus., vol. 13, No. 6, 1922, p. 250) has proposed to put Drillia laevis (Hutt.) into a new subgenus Splendrillia of the genus Melatona Swainson—type Drillia woodsi Beddome. W. L. May (Illustr. Index Tasm. Shells, 1923, pl. 35 Fig. 15) refers woodsi to the genus Austrodrillia Hedley, 1918, so that Splendrillia becomes a synonym of this latter genus, and the Kaawa shell previously listed as Drillia laevis (Hutt.) must be referred to Austrodrillia.
Certain Kaawa shells of the original collection identified previously as Drillia aequistriata Hutt. prove to belong to a new species of Austrodrillia now described below.
Austrodrillia koruahinensis n. sp, (Figs. 36 and 37).
A shell very closely resembling aequistriata, but more densely striated. Fairly large turreted shell, with sharp conical spire a little higher than aperture and canal. Seven whorls; whorls deeply excavated on shoulder and gently convex below. Protoconch (paratype) about 1½ convex, smooth whorls. Suture impressed and margined below by a slightly convex raised spiral band, which descends into the concave sinus-area of shoulder. Outer lip broken; evidently a deep notch in outer lip near suture, for growth-lines are bent sharply and strongly back. Aperture slightly oblique; columella straight above and bent slightly to left near fasciole at base. Anterior canal (paratype) short and fairly broad; rather shallowly notched, so that fascioic is not prominent. Inner lip sharply margined; rather narrowly calloused, with somewhat thick pad of callus at posterior canal.
Sculpture: 11 or 12 axial costae passing up from suture to the slight angle at shoulder, but not developed on the latter; inclined to be faintly nodular at angle, especially on upper whorls. Spiral ornamentation of close-spaced threads (about 9 per mm. on body and penultimate whorls). Base has about 11 larger sub-equidistant spiral threads (including those on fasciole) less prominent towards shoulder. Paratype has 6 raised threads on base and 5 on fasciole.
Dimensions cf holotype (Fig. 36) (apex broken) : Height, 23.7 mm.; diameter, 8.8. mm. Paratype: 18 mm. × 6.3 mm.
Austrotoma ef. scopalveus Finlay.
Kaawa specimens agree moderately closely with Finlay's species (Trans. N.Z. Inst., vol. 56, 1926, p. 253). This applies particularly to a single juvenile shell, though the adults appear to attain a greater size than the type, whilst the body-whorl appears to be more loosely coiled, and, on smaller typical specimens, exposes 6 spirals on the penultimate whorl.
Turris cf. duplex Suter.
The shell recorded by Bartrum (1919, a) as Turris duplex Suter differs from this latter species in the number of ribs and in the possession of some larger spiral threads on the base. The canal is unknown, for the outer lip is broken. As only one specimen is known, its divergence from duplex scarcely seems sufficiently marked to warrant the creation of a new species.
Guraleus ngatuturaensis n. sp. (Figs. 34 and 35).
The new Kaawa species is closely allied to G. (= Mangilia) sinclairi (Smith) (see Hedley Suppl. to Journ. Roy. Soc. N.S.W., 1918, p. M 79), but has its axial ribs finer and more numerous—about 21 on body-whorl, in contrast with 10—16 in sinclairi.
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Fairly small, turreted, fusiform, axially costate shell, with conical spire about 4/3rds height of aperture and canal. 6 convex whorls; shoulder slightly convex to almost flat on spire-whorls, and flat to slightly concave on body-whorl. Spire-whorls angled near middle, but shoulder of body-whorl narrow. Protoconch low, about 1 smooth whorl, followed by a whorl which is spirally lirate, but not axially costate. Subsequent whorls have both spiral and axial sculpture. Suture impressed. Aperture oblique to left, oval, with a distinct angle above and a fairly broad and somewhat short canal below, oblique to left and not notched at base. Outer lip broken. Inner lip thin smooth and narrow. Columella broadly convex, oblique to left.
Sculpture: Axial costae from suture to suture on spire, weaker on shoulder of body-whorl, and gradually dying out on base. Costae narrow, sharply raised; interspaces a little wider than ribs. These latter almost straight on lower half of each whorl, but bent distinctly to left on shoulder forming a shallow V with apex at angle. Close-spaced strong spiral threads (about 12 per mm. on penultimate whorl) prominent, surmounting costae; wider apart and stronger on base.
Dimensions of holotype: Height, 7.1 mm.; width, 2.6 mm.
Genus Pervicacia Iredale, 1924.
Terebra benesulcata Bartrum and a shell in the A.U.C. collection identified by Dr. Marwick as T. tristis Desh. should now be referred to the genus Pervicacia Iredale (Proc. Linn. Soc. N.S.W., vol. 49, pt. 3, 1924, p. 262).
Fresh material shews that while tristis is certainly represented by a single specimen, others previously referred to this species belong to a new species now described as Pervicacia subtilissima n. sp.
Pervicacia subtilissima n. sp.
Elongated sharply turreted axially costate shell close to tristis. Spire four times height of aperture and canal; outline fairly straight. Whorls only slightly convex, 9 on holotype, 6½ on paratype. Body-whorl convex, rapidly contracting to neck. Aperture (paratype) oval, oblique to left, terminating below in short, broad canal bent strongly to left, and moderately deeply notched, giving rise to an oblique wide fasciole bordered by high ridge against base of body-
whorl. Columella straight above, bent to left below. Inner lip narrow and thin. Protoconch (paratype) 3½ or 4 smooth whorls.
Axial ribs not so flexuous as in tristis, more upright and much sharper or narrower at crest; 15 ribs on antepenultimate whorl.
Dimensions of holotype (incomplete): Height, 18.8 mm., diameter, 5.4 mm. Paratype: 10 mm. × 3.2 mm.
Genus Rhizorus Montfort, 1810.
Finlay (Trans. N.Z. Inst., vol. 57, 1926, p. 437) points out that Hedley (Proc. Linn. Soc.N.S.W., vol. 41, 1917, p. 716) indicated that the generic name Volvulella Newton, 1891, must be replaced by Rhizorus Montfort, 1810. At the same time he shews that the New Zealand Recent shells grouped by Suter (Manual, p. 529) with the fossil species Volvulella reflexa (Hutt.) are distinct from this latter, and institutes a new species nesentus to include them.
Two specimens collected from the Kaawa beds differ both from the Recent and the fossil species and constitute a new species.
Rhizorus marwicki n. sp. (Figs. 40 and 41).
Only a single worn specimen, (the holotype) now remains, for the small paratype was accidentally destroyed subsequent to examination.
A tiny, elongate-oval, involute shell with sharp apex and rather narrowly rounded base. Close to reflexa and nesentus, but more tumid than either. Outer or body-whorl broadly convex, narrowing rapidly above to a fairly sharp spire, but more gently below to the narrowly curved base.
Shoulder slightly concave in front, near base of spire; equator of body-whorl about one-third height down from apex. Aperture the whole length of shell; a narrow slit above, but swelling below in accord with narrowing of body-whorl at parietal wall. Outer lip thin, broadly convex, broken above; apparently not reflexed; bent sharply around to join with almost straight short pillar at base. A small chink-like hollow between pillar and initial tumescence at base of body-whorl.
Ornamentation: Strong close-spaced axial striae shewn well by broken paratype, but worn from holotype except at inner lip. Faint traces of about three spiral grooves shewn near base of paratype.
Dimensions of holotype: Height, 2.4 mm.; diameter, 1.35 mm.
Genus Cylichnina Monterosato.
Finlay (Trans. N.Z. Inst., vol. 57, 1926, p. 438) shews that this generic name must replace Cylichnella for many New Zealand species.
Genus Dentalium Linné, 1758.
In the absence of better material than is available, no revision of the Kaawa species of this genus has been attempted.
Nucula ambrosia n. sp. (Figs. 42 and 43).
The shells recorded by Bartrum (1919, a) and Marwick (see Henderson and Grange, N.Z. Geol. Surv. Bull. No. 28, 1926, p. 57)
as Nucula Hartvigiana Pfr. differ from this species in many respects, though undoubtedly closely allied to it, and are therefore given specific rank. In outline the posterior margin is flatter, the flattening beginning higher up, for the hinge is shorter than in hartvigiana. In addition, the radial sculpture is more definite, and there are only 7 concentric ribs per mm. compared with 9 in hartvigiana. Finally, in the hinge, the ligament pit is smaller, narrower, and more oblique, whilst the posterior teeth do not come so far down as in hartvigiana, for they number only 6 instead of 8 or 9.
Shell, small, obliquely subtriangular, highly inequilateral, thin and with pearly interior; ornamented by radial striae and concentric ribs. Beaks small, strongly incurved, approximate, directed back; situated at one-fourth length from posterior end.
Broad shoulder-like folds from beaks to anterior and posterior margins. Anterior dorsal margin sloping, gently convex, with faint sinuosity immediately behind where anterior fold meets margin. Posterior margin then joins with ventral margin in regular convex curve.
Hinge broadly arched, with central, narrow, elongate resilium pit strongly oblique anteriorly. 6 sub-equal transverse teeth behind pit; about 10 in front, becoming smaller and indistinct towards pit. Interior of shell pearly; strong close-spaced striations near basal margin; this latter finely crenulate.
Ornamentation of strong equidistant concentric ribs (7 per mm.) with sub-equal intervening furrows; both crossed by very dense radial striae, especially prominent in furrows.
Dimensions of holotype: Length, 5.1 mm.; height, 2.8 mm. thickness, 1.2 mm.
Nuculana tenellula n. sp. (Figs. 3, 4. and 5).
Dr. Marwick has pointed out (MS.) that the Nuculana listed by Bartrum (1919, a) as Leda bellula A.Ad. is slightly different from that species in that its posterior dorsal surface is more concave, its beak blunter and more upturned, whilst its teeth are fewer and extend less towards the posterior margin or beak. The shells are therefore separated out as a new species named as above.
This new species is a small, strongly inequilateral, concentrically ribbed shell, ovate in form, rounded in front and produced narrowly behind to a rounded slightly uptilted beak. Umbones small, approximate, situate at anterior third, directed beak, with an escutcheon separated from rest of posterior dorsal surface by a distinct fold running from umbones to posterior margin. Escutcheon without concentric markings. Posterior dorsal outline concave with a sharp ridge in middle of escutcheon produced by sharply upturned shell margins; descending very slowly. Ventral margin broadly convex from beak at posterior margin and forming a fairly uniform curve with anterior and anterior dorsal margins.
Teeth transverse, V-shaped; 14 on anterior side, reaching to anterior margin, 10 on posterior side extending little more than half way to beak. Teeth decrease in size towards umbo.
Ornamentation of strong, fairly sharply raised concentric ribs, closer together near beaks than towards middle of shell, and angled at narrow posterior fold; about 6 per mm.
Dimensions of holotype: Length, 6.7 mm.; height, 4 mm.; thickness, 1.6 mm. Paratype, 8.4 mm. × 4.7 mm. × 1.8 mm.
Genus Arca Lamarck, 1799.
Marwick (MS.) remarks on the divergence of the shell listed previously as Arca subvelata Suter from the type. As only two shells have been collected, however, and may represent juvenile forms, more material is required for comparison.
Other Kaawa species are A. novae-zelandiae Smith and a new species recognised as such originally by Dr. Marwick, which has been named Arca (Acar) opuraensis n. sp.
Arca (Acar) opuraensis, n. sp. (Fig. 15).
Known by a single left valve. Elongate, quadrate, ventricose, strongly inequilateral shell with strong concentric and radial ribs yielding imbricated sculpture. Broad swollen beak at about anterior third, from which a strong fold runs to posterior dorsal margin, delimiting posterior dorsal area, and a faint one, with a slight sinus above it, to anterior basal margin. Beak directed forwards, relatively approximate; cardinal ligament area almost obsolete, but a linear anterior area raised along anterior margin and a broad flattened posterior area. Anterior margin descends slowly; sinuous, a slight sinus near beak and then narrowly convex towards prominent angle with sub-vertical sinuous anterior margin. Ventral margin forms strong rounded angle anteriorly, flexed, with an anterior gape, lightly convex. Posterior dorsal margin horizontal, straight. Posterior lateral margin somewhat oblique towards basal margin, lightly concave in middle, strongly and broadly angled above and more narrowly below.
Sculpture reticulated. About 15 very strong rounded concentric ribs, closer together near beaks and more distant below, where lowest 3 or 4 have rather an imbricated structure. Also strong radials, about 3 per mm., developed generally between concentric ribs and dying out on these latter, except towards ventral margin where they cause a crenulation of the concentric sculpture which is especially prominent on posterior area. Grooves between radials subequal to these latter.
Hinge-plate narrow, worn; teeth straight, in oblique series, large, not numerous—about 12 posteriorly and 4 anteriorly—obsolete below beak. Internal margin worn, slightly sinuous, but apparently not crenate.
Dimensions: Length, 8.3 mm.; height, 4.8 mm.; thickness, 2 mm.
Glycymeris waipipiensis Marwick.
Bartrum's (1919, a) record of G. striatularis (Lamk.) should be amended. The species is G. waipipiensis Marwick. Similarly, Marwick (Trans. N.Z. Inst., vol. 54, 1923, p. 72) has shewn that the record of G. globosa is incorrect, the shell being a new species—G. kaawaensis Marwick.
Cuna cerussata n. sp. (Figs. 46 and 47).
Dr. Marwick separated out a shell collected by Bartrum as the Recent Cuna carditelloides Suter, but comparison with topotypes of
that species (Figs. 44 and 45) shews many strong differences. The outline is more rounded, the posterior dorsal margin being broader, more regularly and strongly convex and not so rapidly descending as in carditelloides, the dorsal margin and umbo thus being broader. Further, there is no distinct angle near the posterior margin, whilst, as concerns sculpture, the ribs are much broader in the new species and the interspaces linear.
Shell minute, fairly solid, moderately ventricose, slightly inequilateral, radially ribbed, with fairly broad approximate central beak with distinct oval lunule in front.
Posterior dorsal margin as described; anterior dorsal margin sloping fairly steeply, flat above and then sweeping round in semicircular curve embracing ventral margin.
Sculpture of about 17 broad, flat, subequal, radial ribs (smaller near dorsal margin), with linear intervening grooves. Hinge-plate heavy. Holotype (right valve) shews stout slightly bifid cardinal tooth. Internal basal margin crenate.
Dimensions of holotype: Length, 1.7 mm.; height, 1.8 mm.; thickness, 0.55 mm.
Cardita aoteana Finlay.
Finlay (Trans. N.Z. Inst., vol. 57, 1926, p. 459) shews that the species C. calyculata (L.) is not represented in New Zealand, and states that the Recent New Zealand shells fall in at least two species he institutes—C. brookesi and C. aoteana. The Kaawa shells listed previously as calyculata prove to belong to the species aoteana.
Genus Venericardia Lamarck, 1801.
A number of species of this genus are represented at Kaawa, including difficilis (Desh.), lutea (Hutt.) and 3 new species of the purpurata group, whilst the record of purpurata itself must be expunged. The Kaawa specimens of lutea have the shape and hinge characters of typical lutea, though the ribbing is slightly closer than in the Recent species.
Venericardia koruahinensis n. sp. (Figs. 10 and 11).
Small, rounded-ovate, only slightly inequilateral shell, moderately ventricose, broader than high, and with strong radial ribs. Beaks small, little inflated, approximate, sub-central, fairly strongly curved and with a large oval lunule in front. Anterior end slightly the longer; less broadly rounded than posterior end. Anterior dorsal margin almost flat to gently convex, sloping very gradually to regularly rounded anterior margin. Ventral margin broadly rounded, continuing curves of lateral margins. Posterior dorsal margin gently convex; some paratypes have distinct angle at posterior margin.
No concentric sculpture, but about 22 close-spaced broad, rounded, radial ribs with equal interspaces.
Hinge as in purpurata, except that central cardinal of right valve is narrow. Internal basal margin rather coarsely crenulate.
Dimensions of holotype: Length, 6.5 mm.; height, 5.4 mm.; thickness, 1.8 mm. Paratype: 5.9 mm. × 4.6 mm. × 1.5 mm.
Venericardia (Pleuromeris) miniscula n. sp. (Fig. 12).
Very small, equilateral, sub-circular, moderately ventricose shell, with small poorly-inflated central beaks. Dorsal margin with gradual slope; moderately flat immediately behind beak, and then sweeping round to conform with narrow arc of posterior margin. Flattened, or slightly concave in front with a distinct angle shewn by some para-types at rounded anterior margin. Basal margin semi-circular. Sculpture of about 22 narrowly rounded, close-spaced radial ribs, with equal interspaces. Faint growth-lines visible near ventral margin. Hinge of Pleuromeris type; worn on holotype. Basal margin (paratype) strongly and coarsely crenulate.
Dimensions of holotype: Length, 4.6 mm.; height, 4.6 mm.; thickness, 1.2 mm. Paratype: 3.2 mm. × 3 mm. × 1.05 mm.
Venericardia penerectangularis n. sp. (Figs. 8 and 9).
A fairly small, solid, ventricose, quadrate species with strong radial ribs; near difficulis, but more quadrate and with slight differences in the hinge.
Beaks about anterior fifth, broad, prominent and rounded with fairly small inset heart-shaped lunule in front. Posterior dorsal margin very gently convex, sub-parallel to ventral margin and strongly angled at posterior margin. The latter almost straight, subvertical, with a rounded-rectangular angle at basal margin. Basal margin flat to lightly convex, sloping gradually up to fairly sharply-rounded anterior margin. Anterior dorsal margin flat, or faintly concave, near beak, then descending steeply, gently convex, to anterior margin.
Sculpture (slightly worn) of about 20 strong, rounded, radial ribs with somewhat flattened crests and equal interspaces. Ribs rendered faintly nodular by imbricating development of growth-lines, which are prominent in interspaces as raised threads.
Hinge-plate heavy. Posterior cardinal of holotype (left valve) sub-parallel to dorsal margin; anterior cardinal small and broadly triangular. In right valve (paratype) central and posterior cardinals sub-parallel to dorsal margin. Hinge otherwise as in difficlis. Internal basal margin coarsely and strongly crenulate.
Dimensions of holotype (left valve): Length, 13.5 mm.; height, 10.5 mm.; thickness, 4.2 mm. Paratype (right valve): 13 mm. × 10.25 mm. × 4 mm.
Genus Notomyrtea Iredale, 1924.
Finlay (Trans. N.Z. Inst., vol. 57, 1926, p. 461) places shells previously recorded from the Kaawa beds as Lucinida concinna (Hutton) and L. cf. levifoliata Marshall & Murdoch in the new subgenus Pteromyrtea of the genus Notomyrtea Iredale (Proc. Linn. Soc. N.S.W., vol. 49, pt. 3, 1924, p. 206). The Kaawa shells compared with levifoliata appear to agree well with that species.
Diplodonta zelandica (Gray).
Finlay (loc. cit., pp. 461-2) wishes to dismiss Diplodonta from lists of New Zealand fauna, and replace it by Zemysia gen. nov., but
records no differences of the New Zealand shells from those classed in the genus Diplodonta elsewhere.
Rochefortula kaawaensis n. sp. (Figs. 51 and 52).
Finlay (loc. cit., pp. 464-5) institutes the new genus Rochefortula to include the Recent New Zealand species Rochefortia reniformis Suter (Trans. N.Z. Inst., vol. 40, 1908, p. 357) and predicts the discovery of Tertiary ancestors, one of which has now appeared from the Kaawa beds.
The solitary shell representing the new species has the characters of the right valve of reniformis, for its anterior end is the longer and its beak directed back, but differs from this latter species in having its ends more bluntly rounded, whilst the concentric lines are faint. Further, it declines more steeply at the posterior end, and the ventral margin is flattened.
Shell small, poorly-inflated, sub-quadrate, rounded; only slightly inequilateral, almost smooth, with small inconspicuous beak near the middle. Dorsal margins broadly convex; posterior margin slopes fairly steeply and is well rounded. Anterior margin descends more gradually and forms a broadly rounded angle at ventral margin. This latter flat at middle and then conforming anteriorly with strong sweep of rounded anterior margin.
Sculpture (slightly worn): Faint growth-lines and traces of dense weak radial striae, especially towards basal margin. These latter may not represent true sculpture, however, for shell is worn. Hinge (right valve) shews a fairly heavy hinge-plate with resilium pit below the beak and a strong divergent, raised cardinal on either side. Internal margin smooth.
Dimensions of holotype: Length, 6 mm.; height, 4.7 mm.; thickness, 1.3 mm.
Genus Macoma Leach, 1819.
Finlay (loc. cit., p. 435) states that the generic name Tellina s. str. is inapplicable to New Zealand species, and refers many of them to the genus Macoma Leach, 1819. Amongst Kaawa species of Tellina listed by Bartrum (1919, a) is huttoni sterrha based on Suter's determination of a single valve. The addition of fresh material shews, however, that this is a new species described below as Macoma subtriquetra n. sp.
The other species represented are M. edgari (Iredale) (= glabrella), M. gaimardi (Iredale) (= alba), M. huttoni (Smith) and M. spenceri (Suter). The species Tellina urinatoria Suter appears to belong to the new genus Maoritellina of Finlay (loc. cit., pp. 465-6).
Macoma subtriquetra n. sp. (Figs. 1 and 2).
Unfortunately, all the specimens of this species are left valves and it is impossible to obtain the hinge-characters sufficiently clearly to determine whether or not the shell should be referred to the genus. Barytellina Marwick (Proc. Mal. Soc., vol. 16, 1924, p. 26). It is, however, very near Macoma huttoni sterrha (Suter), but differs from it in its smaller size and different outline.
Shell very small, thin, ovate to sub-trigonal, generally compressed, inequilateral; small, low, inconspicuous beaks near anterior third. Anterior end the longer, broadly rounded; posterior end much narrower. An indistinct fold runs from beak to angle of posterior margin. Anterior dorsal margin flattish above, descending steeply. Posterior margin strongly angled at basal margin. The latter broadly convex, though with a faint sinus behind.
One specimen, apparently of this species, shews a more rotund outline, combined with greater convexity.
Sculpture: Growth-lines developed into faint striae visible on parts of a paratype.
Hinge as in huttoni. Pallial sinus imperfectly visible. Internal margin smooth.
Dimensions of holotype: Length, 7.5 mm.; height, 5.7 mm.; thickness, 1.1 mm.
Semeloidea donaciformis n. gen. and sp. (Figs. 49 and 50).
A shell new to New Zealand, and puzzling in its relationships, for it has hinge-characters similar to those of Semcle, but differs from that genus in outline and in coarsely crenulated ventral margin-features in which it resembles Donax.
The material available is a single, perfectly preserved left valve. It exhibits characters so distinct from those of all other genera known to the authors that its inclusion in any one of them—for example, Semele, which appears to be its closest relative—would be highly undesirable. As an alternative, the new genus Semeloidea has been created.
The genotype is a small, thin, almost equilateral, ventricose, subtrigonal-ovate shell, with breadth greater than height. Beak small, sharp, directed forwards, situated at the middle. No lunule or escutcheon. Anterior and posterior ends rounded, the dorsal margins with a moderate slope and gently convex, the former slightly flatter than the latter. Basal margin horizontal, almost straight in middle.
Sculpture of microscopic concentric growth-striae, with strong radial rounded fold-like ribs prominent at the extremities, but rapidly becoming obsolete along ventral margin and also fading rapidly away towards upper half of shell. About 5 strong radial ribs at each extremity, with equal interspaces.
Interior grooved and marginally crenulated in correspondence with external sculpture. Adductor scars distinct, equal, circular. Pallial sinus not shewn, as surface is slightly etched. Hinge (left valve): 2 strong, raised cardinal teeth below beak, followed by a strong, long, gently curved posterior lateral sub-parallel to posterior dorsal margin. Anterior cardinal much the stronger, thickening below and directed obliquely forwards; the other sub-vertical, distinctly curved posteriorly.
Resilifer indicated by faint striations, sub-parallel to posterior lateral, visible in pit between it and cardinals.
Dimensions: Length, 7.9 mm.; height, 6 mm.; thickness, 1.9 mm.
Resania exoptata n. sp. (Figs. 13 and 14).
Known by only two specimens, both somewhat imperfect. Differs from Recent R. lanceolata Gray in possessing straighter dorsal surfaces and in the distinctly raised nature of posterior dorsal surface.
Fairly large, lanceolate, thin, slightly inequilateral, rather compressed shell with very small sharp beaks near the middle; sculpture of concentric growth-lines. Anterior end slightly the longer; posterior end with broad indistinct fold from beak to posterior margin. Posterior gape of valves.
Anterior dorsal margin straight with very gentle to obtuse angle with narrowly rounded anterior margin. Posterior dorsal margin almost flat, but with slight convex bulge not far from beak, where margin rises steeply from dorsal surface. Posterior margin broken away; growth-lines indicate that it is less narrowly rounded than anterior. Basal margin convex; only slight curvature.
Ornamentation of growth-lines; traces of original colour remain giving alternations of pale brown and darker purplish concentric bands of varied width.
Interior not visible.
Dimensions of holotype: Length, 26.5 mm.; height, 11 mm. Large paratype (imperfect) has approximate proportions (estimated) as follows:—Length, 62 mm.; height, 27 mm.; double thickness, 11 mm.
Tawera bartrumi Marwick.
In a recent revision of New Zealand Veneridae, Marwick (loc. cit., pp. 614-615), relegates Chione spissa, C. mesodesma and C. meridionalis of Bartrum (1919, a) to Tawera bartrumi n. gen. et sp.
Gomphina (Gomphinella) maorum Smith.
Marwick (loc. cit., p. 631) institutes the new subgenus Gomphinella to include this species.
Eumarcia kaawaensis Marwick.
Paphia curta (Hutton) of Bartrum (1919, a) is referred by Marwick (loc. cit., p. 627) to this species.
Nemocardium finlayi n. sp. (Fig. 48).
Finlay (loc. cit., p. 471) recommends the use of the genus name Nemocardium Meek, 1876, to cover Protocardia pulchella (Gray) and an ancestral Tertiary species Nemocardium semitectum Marwick (Trans. N.Z. Inst., vol. 56, 1926, p. 312).
Better material than that previously available has shewn that the Kaawa species, previously recorded as pulchellum, differs from this shell and from semitectum in having much heavier flat-topped ribs, with only narrow interspaces, whilst the spines on the posterior slope are larger, blunter and more distant one from another. The new species is a thin, fragile, sub-circular, slightly inequilateral, strongly ventricose shell with strong close-spaced radial ribs. Beaks fairly large, tumid, slightly anterior. Dorsal margins descend in arcuate curve to lateral margins and join with them and basal margin in sub-circular curve.
Sculpture: Dense, strong, rounded radial ribs, 4 per mm., flattened on top and with narrow interspaces. Concentric sculpture not detected, though axial ribs are raised into long blunt spines near beak on posterior slope.
Hinge imperfect; internal basal margin finely notched. Dimensions of holotype: Length, 9.2 mm.; height, 8:6 mm.; thickness, 3.8 mm.
List of Mollusca from Kaawa Beds.
The following list includes all those species examined by the authors. Recent species are indicated by an asterisk.
Alcithoe mackayi Marwick.
Alcithoe parva Marwick.
Alcithoe propearabicula Powell & Bartrum.
*Anomia trigonopsis Hutton.
*Arca (Barbatia) novae-zelandiae E. A. Smith.
Arca (Acar) opuraensis Powell & Bartrum.
Arca subvelata Suter.
Austrodrillia koruahinensis Powell & Bartrum.
*Austrodrillia laevis (Hutton).
Austrofusus ngatuturaensis Powell & Bartrum.
Austrofusus propenodosa (Bartrum).
Austrotoma cf. scopalveus Finlay.
*Barnea similis (Gray).
Baryspira exsputa Powell & Bartrum.
Baryspira cf. hebera (Hutton).
*Cardita aoteana Finlay.
Cochlis cf. haweraensis (Marwick).
Cochlis notocenica (Finlay).
Cominella facinerosa Powell & Bartrum.
Crypta opuraensis Powell & Bartrum.
Crypta turnialis Powell & Bartrum.
Cuna cerussata Powell & Bartrum.
Dentalium several spp.—no revision attempted.
*Diplodonta zelandica (Gray).
*Divaricelli cumingi (Ad. & Ang.).
Dosinia kaawaensis Marwick.
*Dosinia (Dosinia) lambata Gould.
*Dosinia (Phacosoma) maoriana Oliver.
*Dosinia cf. subrosa (Gray).
Elachorbis cingulatus (Bartrum).
*Emarginula striatula Q. and G.
Eumarcia kaawaensis Marwick.
*Gari lineolata (Gray).
*Gari stangeri (Gray).
Glycymeris kaawaensis Marwick.
*Glycymeris modesta (Angas).
Glycymeris waipipiensis Marwick.
Guraleus ngatuturaensis Powell & Bartrum.
Hipponyx sp. Kaaivatina turneri Powell & Bartrum.
Lima cf. colorata Hutton.
*Macoma edgari Iredale.
*Macoma gaimardi (Iredale).
*Macoma huttoni (Smith).
*Macoma spenceri (Suter).
Macoma subtriquetra Powell & Bartrum.
*Mactra discors Gray.
*Mactra scalpellum Reeve.
*Maoritellina urinatoria (Suter).
Marginella hesterna Powell & Bartrum.
*Melanopsis trifasciata Gray.
Miltha neozelanica Marsh. & Murd.
Montfortula kaawaensis (Bartrum).
*Murex zelandicus Q. & G.
*Myodora antipodum Smith.
Nemocardium finlayi Powell & Bartrum.
Neojanacus kaawaensis Powell & Bartrum.
Figs. 8.—Venericurdia penerectangularis n. sp.; paratype. 13 mm. × 10.25 mm.
Figs. 9.—Venericardia penerectangularis; holotype. 13.5 mm. × 10.5 mm.
Figs. 10.—Venericardia koruahinensis n. sp; holotype. 6.5 mm. × 5.4 mm.
Figs. 11.—Venericardia koruahinensis; paratype. 5.9 mm. × 4.6 mm.
Figs. 12.—Venericardia (Pleuromeris) miniscula n. sp. 4.6 mm. × 4.6 mm.
Fig. 13.—Resania exoptata n.sp.; paratype. Height, 27 mm.
Fig. 14.—Resania exoptata; holotype. 26.5 mm. × 11 mm.
Fig. 15.—Arca (Acar) opuraensis n. sp. 8.3 mm. × 48 mm.
Figs. 16-17.—Neojanacus kaawaensis n. sp.; holotype. 6 mm. × 6.7 mm.
Figs. 18-19.—Neojanacus kaawaensis; paratype. 3.2 mm. × 3.2 mm.
Fig. 20.—Tugali opuraensis n. sp. 11 mm. × 6 mm.
Figs. 21-22.—Trochus bibaphus n. sp. 9.2 mm. × 10.7 mm.
Figs. 23-24.—Crypta turnialis n. sp. 31.5 mm. × 19.25 mm. × 11.6 mm.
Fig. 25.—Crypta opuraensis n. sp. 25 mm. × 15 mm.
Figs. 26-27.—Cominella facinerosa n. sp. 29 mm. × 20.5 mm.
Figs. 28-29.—Baryspira exsputa n. sp. 5.7 mm. × 2.8 mm.
Figs. 30-31.—Marginella hesterna n. sp. 4.5 mm. × 28 mm.
Fig. 32.—Odostomia sp. 4.8 mm. × 2.3 mm.
Fig. 33.—Hipponyx sp. 5.4 mm. × 4.6 mm.
Figs. 34-35.—Guraleus ngatuturaensis n. sp. 7.1 mm. × 2.6 mm.
Fig. 36.—Austrodrillia koruahinensis n. sp.; holotype. 23.7 mm. × 8.8 mm.
Fig. 37.—Austrodrillia koruahinensis; paratype. 18 mm. × 6.3 mm.
Fig. 38.—Pervicacia subtilissima n. sp.; holotype. 18 mm. × 5.4 mm.
Fig. 39.—Pervicacia subtilissima; broken paratype. Diam., 3.7 mm.
Figs. 40-41.—Rhizorus marwicki n. sp. 2.4 mm. × 1.35 mm.
Figs. 42-43.—Nucula ambrosia n. sp. 5.1 mm. × 2.8 mm.
Figs. 44-45.—Cuna carditelloides Suter. Recent topotype. 2.5 mm. × 2 mm.
Figs. 46-47.—Cuna cerussata n. sp. 1.7 mm. × 1.8 mm.
Fig. 48.—Nemocardium finlayi n. sp. 9.2 mm. × 8.6 mm.
Figs. 49-50.—Seme [ unclear: ] idea donaciformis n. gen. et sp. 7.9 mm. × 6 mm.
Figs. 51-52.—Rochefortula kaawaensis n. sp. 6 mm. × 4.7 mm.
Figs. 53 54.—Xenophallum kaawaensis n. sp. 67 mm. × 48 mm.
Figs. 55-56.—Struthiolaria arthritica n. sp. 56.5 mm. × 44 mm.
Figs. 57-58.—Austrofusus (Neocola) ngatuturuensis n. sp. 24 mm. × 14.8 m.m.
Figs. 59-60.—Verconella koruahinensis n. sp. 71.4 mm. × 36.5 mm.
Fig. 61,—Alcithoe propearatricula n. sp. 32.8 mm. × 17.8 mm.
Fig. 62.—Struthiolaria illepida n. sp. Height, 61.5 mm.
Figs. 63-64.—Struthiolaria pseudovermis n. sp. 40 mm. × 25.5 mm.
Bartrum-Powell.—Mollusca from Kaawa Creek.
*Notomyrtea concinna (Hutton).
Notomyrtea levifoliata (Marsh. & Murd.)
Nucula ambrosia Powell & Bartrum.
*Nucula nitidula A. Ad.
Nuculana tenellula Powell & Bartrum.
Odostomia cf. sherriffi Hutton.
Olivella neozelanica (Hutton).
Pecten williamsoni Zittel.
Pecten spp. not determined.
Pervicacia benesulcata (Bartrum).
Pervicacia subtilissima Powell & Bartrum.
*Pervicacia tristis (Desh.).
Resania exoptata Powell & Bartrum.
Rhizorus marwicki Powell & Bartrum.
Rochefortula kaawaensis Powell & Bartrum.
Semeloidea donaciformis Powell & Bartrum.
*Spectamen cf. egena (Gould).
*Spisula aequiateralis (Desh.).
Spisula aequilateralis gilberti Bartrum.
*Spisula ordinaria (Smith).
Struthiolaria arthritica Powell & Bartrum.
Struthiolaria illepida Powell & Bartrum.
Struthiolaria pseudovermis Powell & Bartrum.
Tawera bartrumi Marwick.
*Thyasira flexuosa (Montagu).
Trochus bibaphus Powell & Bartrum.
Tugali kaawaensis Bartrum.
Tugali opuraensis Powell & Bartrum.
“Turbo” postulatus Bartrum.
Turris cf. duplex Suter.
Turritella cf. huttoni Cossm.
*Turritella symmetrica Hutton.
Uber kaawaensis Marwick.
Uber propeovatus Marwick.
*Venericardia difficilis (Desh.).
Venericardia koruahinensis Powell & Bartrum.
*Venericardia lutea (Hutton).
Venericardia (Pleuromeris) miniscula Powell & Bartrum.
Venericardia penerectangularis Powell & Bartrum.
Verconella koruahinensis Powell
Xenophalium kaawaensis Powell & Bartrum.
Zegalerus crater Finlay.
In addition to the above, there are included also in the list of determinations by Dr. Marwick (see Henderson and Grange, N.Z. Geol. Surv. Bull. No. 28, 1926, p. 57) the following species:—
Acteon minutissimus Murdoch.
Alcithoe arabicula Marwick.
*Atrina zelandica (Gray).
Cerithiopsis aequicincta Suter.
*Corbula zelandica Q. & G.
Drillia cf. callimorpha Suter.
*Guraleus‡ (=Mangilia) sinclairi (E. A. Smith.).
*Haliotis cf. iris Martyn.
*Lima suteri Dall.
*Mytilus canaliculus Martyn.
Odostomia georgiana Hutton.
*Ostrea angasi Sow.
*Rhizorust† (=Volvulella) reflexa (Hutton).
Turris cf. bimarginatus Suter.
Zaclys§ (= Cerithiopsis) aequi-
The shells on this supplementary list have not been examined by the authors. It is probable that Guraleus sinclairi of this list should be referred to the new species ngatuturaensis, and Rhizorus reflexa to the new species marwicki.
[Footnote] ‡ See Finlay, Trans. N. Z. Inst., vol. 57, 1926, p. 437.
[Footnote] † See Hedley, Rec. Aust. Mus., vol. 13, No. 6, 1922, p. 311.
[Footnote] § See Finlay, loc. cit., pp. 381-2.
If consideration be given only to exact specific identifications, with the inclusion of unidentified types which are almost certainly extinct, the porportion of Recent forms in the fauna works out at 36 per cent. If all probable Recent forms be included, it is 39 per cent.
The appended list includes the papers to which most frequent reference has been made in the text of the present paper:—
List of Literature.
Bartrum, J. A., 1919 a. A Fossiliferous Bed at Kawa Creek, West Coast, South of Waikato River, Trans. N.Z. Inst., vol. 51, pp. 101-106.
—— 1919 b. New Fossil Mollusca, Ibid., pp. 96-100.
Finlay, H. J., 1926 a. New Shells from New Zealand Tertiary Beds: Part 2, Trans. N.Z. Inst., vol. 56, pp. 227-258.
—— 1926 b. A Further Commentary on New Zealand Molluscan Systematics. Trans. N.Z. Inst., vol. 57, pp. 320-485.
Hedley, C. 1917. Studies on Australian Mollusca, pt. 13, Proc. Linn. Soc. N.S.W., vol. 41, pt. 4, pp. 680-719.
—— 1918. A Check List of the Marine Fauna of New South Wales, Pt. 1. - Mollusca, Supplt. to Journ. Roy. Soc. N.S.W., vol. 51, pp. M 1-120.
—— 1922. A Revision of the Australian Turridae, Rec. Austr. Mus., vol. 13, No. 6, pp. 213-359.
—— 1924. Some Naticoids from Queensland, Rec. Austr. Mus., vol. 14, No. 3, pp. 154-161.
Henderson, J., and Grange, L. I., 1926. The Geology of the Huntly-Kawhia Subdivision, N.Z. Geol. Surv. Bull. No. 28 (n. s.).
Iredale, T., 1915. A Commentary on Suter's Manual of the New Zealand Mollusca, Trans. N.Z. Inst., vol. 47, pp. 417-497.
—— 1924. Results of Roy Bell's Molluscan Collections, Proc. Linn. Soc. N.S.W., vol. 49, pt. 3, pp. 179-278.
—— 1927. A Review of the Australian Helmet Shells, Rec. Austr. Mus., vol. 15, No. 5, pp. 351-354.
Marshall, P., and Murdoch, R., 1920. Some Tertiary Mollusca, with descriptions of New Species, Trans. N.Z. Inst., vol. 52, pp. 128-136.
Marwick, J., 1923. The Genus Glycymeris in the Tertiary of New Zealand, Trans. N.Z. Inst., vol. 54, pp. 63-80.
—— 1924 a. The Struthiolariidae, Trans N.Z. Inst., vol. 55, pp. 161-190.
—— 1924 b. The Tertiary and Recent Naticidae and Naricidae of New Zealand, Ibid., pp. 545-579.
—— 1924 c. Zealeda and Barytellina, new fossil Molluscan Genera from New Zealand, Proc. Mal. Soc. (London), vol. 16, pt. 1, pp. 25-26.
—— 1926 a. Molluscan Fauna of the Waiarekan Stage of the Oamaru Series. Trans. N.Z. Inst., vol. 56, pp. 307-316.
—— 1926. New Tertiary Mollusca from North Taranaki, Ibid., pp. 317-331.
—— 1927. The Veneridae of New Zealand, Trans. N.Z. Inst., vol. 57. pp. 567-635.
Oliver, W. R. B., 1923. Notes on New Zealand Pelecypods, Proc. Mal. Soc. (London), vol. 15, pt. 4, pp. 179-188.
Powell, A. W. B., 1924. Notes on New Zealand Mollusca, N.Z. Journ. Sc. & Techn., vol. 6, pp. 282-6.
—— 1926. Mollusca from 100 Fathoms off Lyttelton, with Descriptions of Four New Species, and also a New Pliocene Fossil. Rec. Cant. Mus., vol. 3, pt. 1, pp. 43-50.
Suter, H., 1913. Manual of the New Zealand Mollusca, Wellington.
—— 1915. Revision of the Tertiary Mollusca of New Zealand, Part II., N.Z. Geol. Surv. Pal. Bull. No. 3.