New Species of New Zealand Mollusca from Shallow-water Dredgings.
[Read before the Auckland Institute, 4th October, 1929; received by Editor, 6th November, 1929; issued separately, March 31st, 1930].
In this part thirteen new species are added to the New Zealand Fauna. Of this number, seven represent genera not previously recorded from New Zealand waters. For some of these it has been found necessary to propose two new genera and a subgenus.
In subsequent parts it is proposed to describe a number of small new species and in the final part publish faunal lists from several dredging stations around the New Zealand coast. These will be from the North Island and should serve as an interesting comparison with the two Southern lists previously published by the writer; off Lyttelton in 100 fathoms (1926) and Puyseger Point in 100–170 fathoms (1927).
The writer is greatly indebted to Mr. W. La Roche, of Auckland, and Mr. H. Hamilton, now of Rotorua, for the use of valuable material. The writer is also indebted to The New Zealand Institute for a research grant allotted in 1925, for the purchase of microscopic equipment and literature. These have proved very useful in connection with a number of papers published since that date.
Genus Cuna Hedley, 1902.
Type Cuna, concentrica Hedley.
Cuna mayi n. sp. (Figs. 1 and 2).
Shell small, solid, trigonal, equivalve, almost equilateral, sculptured with ten broad flat radial ribs with narrow shallow interspaces about a quarter the width of the ribs. Beaks close together, prodissoconchs small, smooth and rounded, marked off by a narrow groove. Anterior slope steep, almost straight, subangled below on meeting the rounded basal margin. Posterior slope similarly steep but subangled at a higher point, the basal margin ascending accordingly. Lunule distinct, long and narrow. Basal margin thin and smooth, not conspicuously indented between the ribs. Interior smooth and shining, the ribbing of the exterior showing through. Hinge typical. Adductor-scars subequal, very distinct. Colour pale-buff to dull-white.
Length 1.8 mm., height 2.25 mm., thickness 1.25 mm. (two valves).
Holotype and figured paratype presented to Auckland Museum.
Habitat.—10–12 fathoms off Wanganui (type), N.Z. (W. La Roche, 1927); 6 fathoms off Mangonui (W. La Roche); 12 fathoms, Rangaunu Bay (W. La Roche, 1923).
Differs from the Tasmanian C. delta Tate and May in having much stronger and more uniform sculpture, the radials not becoming obsolete towards the margin.
Four Recent species are now known from New Zealand waters.
C. laqueus Finlay (1926A), Snares Is. and Southern N.Z. in deep water.
C. otagoensis Powell (1927), Southern N.Z. in deep water.
C. carditelloides Suter. Off Lyttelton in 100 fathoms.
C. mayi Powell. Northern N.Z. in shallow water dredgings.
Genus Benthocardiella n. gen.
Type B. pusilla Powell.
The genus stands nearest to Condylocardia, having a similar proportionately large prodissoconch but divergent hinge characters which constitute the reason for separating this species as the type of a new genus.
In the right valve there are three cardinals, an elongated anterior and two posterior. In the left valve there are two cardinals, one anterior and the other posterior. There is also in the right valve an anterior thickening of the valve edge high up near the hinge plate, interlocking with a small lateral in the opposite valve. The resilium pit is spoon-shaped and central and the adductor-scars are subequal as in Condylocardia. The shell is thin and fragile and the surface smooth, except for almost obsolete concentric growth lines.
In Condylocardia there are four cardinals in the right valve and two in the left. The posterior cardinal in the left valve of Bentho-cardiella differs from that of Condylocardia in having a prominent hook at the proximal end. In the right valve the two posterior cardinals are completely separated, not distal projections confluent with hinge line and valve margin as in Condylocardia. The anterior lateral differs in being situated higher up near the hinge line.
Benthocardiella pusilla n. sp. (Figs. 4 and 5).
Shell minute, globose, equivalve, almost equilateral, semitransparent, thin and fragile. Surface smooth and glossy with rather close and slightly irregularly spaced almost obsolete concentric growth lines. Prodissoconch large with a projecting rounded rim, produced anteriorly and posteriorly into swollen upturned processes. Anterior and posterior dorsal slopes steep, gently arcuate, subangled below on meeting the broadly convex ventral margin. The anterior end is slightly more produced than the posterior, resulting in the subangle being slightly higher in front. In the right valve there is first a thickening of the valve edge towards the hinge-plate forming an clongated pseudo-lateral, confluent at the proximal end and elsewhere parallel with an elongated strong anterior cardinal; then the central spoon-shaped resilium pit, followed by two posterior cardinals. The upper posterior cardinal originates high up on the valve margin, spreads in a curve along hinge line and then bends sharply downwards. The lower posterior cardinal borders the lower edge of hinge-plate and is everywhere separated from the upper cardinal. In the
left valve there is a rather short anterior lateral situated high up towards hinge line, near and parallel to the anterior edge of valve, with a slight groove between it and valve edge for the accommodation of the thickened edge of the opposite valve. Parallel to this is a large elongated anterior cardinal separated by a moderately wide and deep cavity for the reception of a similar cardinal in the right valve; then the resilium pit, followed by an elongated posterior cardinal prominently hooked at the proximal end and not reaching to the top of hinge line. There are two subequal adductor-scars, one on each side near edge of valve, at about half height of shell. Colour white.
Length, 0.8 mm.; height, 0.8 mm.; thickness, 0.4 mm. (two valves).
Holotype and figured paratypes presented to Auckland Museum.
Habitat, off Wanganui in 10–12 fathoms, N.Z. (dredged by Mr. W. La Roche, 1927); Rangaunu Bay in 12 fathoms (dredged by Mr. W. La Roche).
Genus Cirsonella Angas, 1877.
Type C. australis Angas.
Cirsonella consobrina n. sp. (Figs. 13 and 14).
Shell minute, turbinate, white, glossy, thick and solid with narrow umbilicus. Whorls 3 ¼, including small smooth protoconch of one lightly convex whorl, very rapidly increasing. Spire low, about one-third height of aperture. Whorls evenly rounded and smooth with the exception of about eight fine closely-spaced spiral threads around the umbilical area. The base rapidly curves to a narrow perforation about one-eleventh the major diameter of the base. Suture impressed, submargined by a narrow faint ridge. Aperture circular, oblique, overhanging above. Peristome continuous, thick, especially above from the suture towards the periphery.
Height, 0.8 mm.; major diameter, 1.2 mm.; minimum diameter, 0.9 mm.
Holotype presented to the Auckland Museum, paratypes in author's collection.
Habitat, Mangonui Heads in 6 fathoms (type) (dredged W. La Roche, 1922); Rangaunu Bay in 12 fathoms (dredged W. La Roche, 1922).
This shell resembles the Tasmanian C. weldii T. Woods in shape and glossy surface. The Tasmanian species however differs in being entirely smooth without spirals in the umbilical area. Two other New Zealand species are known, C. densilirata Suter and C. parvula Powell (1926).
Genus Zeminolia Finlay, 1926.
Type Minolia plicatula Murdoch & Suter.
Zeminolia tryphenensis n. sp. (Figs. 16, 17 and 18).
Shell small, depressed turbinate, widely umbilicated. Whorls 5, including a small bulbous protoconch of one whorl. Sculpture consisting of rounded spiral ridges, three on first post-nuclear whorl,
four on second and third and five on upper part of body-whorl. Interspaces each with a small spiral thread and three or four on shoulder. On the upper half of the base there are six closely spaced spiral ribs about half the strength of those on the spire. On the lower part of the base and within the umbilicus are six strong widely spaced spiral ribs, even more prominent than those on the spire whorls. The post-nuclear whorls are crossed by moderately strong slightly retractive axial riblets, strong on spire whorls and umbilical area but absent from the upper part of the base. The umbilical spirals are crenulated by the axial riblets. Shoulder flat-
tened. Suture impressed. Aperture circular. Peristome almost continuous. Umbilicus about ¼ of the major diameter, deep and scalar. Colour pale pinkish-buff marked with regularly spaced square reddish-brown blotches radiating from suture and confined 10 the shoulder. On the base there are an irregularly blotched and ill defined second series in two rows.
Height, 5.75 mm.; major diameter, 6.25 mm.; minimum diameter, 5.5 mm.
Holotype in author's collection.
Habitat, Tryphena Bay in 6 fathoms, Great Barrier Island (dredged by Mr. W. La Roche, 1924).
This species stands nearest to Z. semireticulata Suter, from which it differs in sculpture.
As the dentition of tryphenensis is not known it is placed provisionally in Finlay's genus Zeminolia. The relationship of this genus and Zetela with the Australian Spectamen has yet to be determined. Fortunately the writer has obtained a living specimen of egenum and a slide of the dentition has been prepared and is here figured together with that of Zethalia zelandica and the New South Wales Spectamen philippensis.
The radula of egenum proves to be Umbonoid, very similar to that of Zethalia, so Finlay's genus Antisolarium may now be confidently used for egenum and its Tertiary ancestor.
The writer has on two occasions used the genus Spectamen for the New Zealand series but only provisionally until the types of Finlay's genera could be examined for their dentition. It was considered premature to create new genera on shell characters in a group where parallelism of these characters has been shown in species belonging to different families.
All the laterals and the central tooth in egenum are much longer and more slender than in Zethalia. The central has a simple chisel-shaped cutting edge and the laterals are each produced on the inner side into blunt cutting points as in Zethalia. Both Zethalia and Antisolarium have four laterals on either side of a central and a profusion of finely cusped slender marginals. The radula of Spectamen on the other hand is entirely different, being very similar to that of Calliostoma with its recurved central and lateral teeth all finely cusped, the central on both sides and the laterals on the outer slopes only. There are three laterals on either side of a central tooth and the marginals are fewer, plain, smooth and slender, regularly concavely arched, extending from the outer edge to about the second lateral.
Double vertical series of elongated interlocking plates are present in both Zethalia and Antisolarium. These are situated on either side between the laterals and the marginals and are almost obscured by the latter.
Genus Nobolira Finlay, 1926.
Type Lironoba polyvincta. Finlay.
Nobolira bollonsi n. sp. (Fig. 7).
Shell small, elongate-conical, thick and solid, sculptured with spiral ridges. Whorls 5, including a typical protoconch of two whorls, sculptured with five raised, rounded spiral ridges. First post-nuclear whorl with two main flat-topped raised spiral cords, the lower one slightly the stronger and two inconspicuous spiral threads, one at upper suture and the other at lower suture. On the penultimate whorl four spiral cords have been attained by the growth of the sutural threads of the early whorls. The third spiral which equals the lower of the main cords on early whorls is still the strongest. On
Fig. 1.—Cuna mayi n. sp. (holotype).
Fig. 2.—Cuna mayi n. sp. (paratype).
Fig. 3.—Seilarex exaltatus n. sp. (holotype).
Fig. 4.—Benthocardiella pusilla n. gen. and sp. (holotype).
Fig. 5.—Benthocardiella pusilla n. gen. and sp. (paratypes).
Fig. 6.—Nobolira (Adolphinoba) finlayi n. subgen. and sp. (holotype).
Fig. 7.—Nobolira bollonsi n. sp. (holotype).
Fig. 8.—Icuncula terebra n. sp. (holotype).
Fig. 9.—Liratilia compta n. sp. (holotype).
Fig. 10.—Pliciscala (Nodiscala) ahiparana n. sp. (holotype).
Fig. 11.—Altispecula elegantula n. sp. (holotype).
Fig. 12.—Altispecula elegantula n. sp. (paratype).
Figs. 13 and 14.—Cirsonella consobrina n. sp. (holotype).
Fig. 15.—Zebittium editum n. sp. (holotype).
the body-whorl there are eight spiral ridges, four above the aperture and four below on base. The interspaces above are about 2½ times the width of the cords and below they gradually diminish from about 1½ to 1. Spire about twice height of aperture. Outline of whorls lightly convex. Body-whorl with sharply angled periphery caused by the strongly developed third spiral cord. Aperture circular. Peristome continuous, smooth and rounded, bordered along outer and basal lips by a heavy rounded varix from which it is separated by a groove and a shallow excavation above and below. On the parietal wall the peristome is separated from the base by a similar narrow groove. Colour pure-white.
Height, 2.5 mm.; diameter, 1.3 mm.
Holotype in author's collection.
Habitat, off Poor Knights Islands in 60 fathoms. N.Z.
Named in honour of the late Captain J. Bollons, who dredged the material from which this specimen was found.
This species is related to the Tasmanian schoutanica May and makes the first Recent species of the genus to be described from New Zealand.
In his paper on New Zealand Molluscan Systematics, Finlay (1926A, p. 377) erroneously described the protoconch of Nobolira as smooth and glossy like Linemera. This should read as given in his first description (1926, p. 227–288), “Shells very similar to Lironoba but with a spirally lirate protoconch.”
Subgenus Adolphinoba n. subgen.
Type A. finlayi Powell.
This subgenus is provided for a series of Australasian shells with spirally lirate protoconchs as in Nobolira but of lighter build with a thin simple peristome, not thickened and duplicated as characteristic of Nobolira, Lironoba and Merelina.
The protoconchs in both Nobolira and Adolphinoba are similarly sculptured, the discriminating character being in the form of the peristome. A typical Australian member of the subgenus is represented by Gatliff and Gabriel's Rissoa wilsonensis from Victoria and Tasmania.
Nobolira (Adolphinoba) finlayi n. sp. (Fig. 6).
Shell small, elongate-conical, sub-gradate, thin and fragile, sculptured with spiral ridges. Whorls 4½, including a large dome-shaped protoconch of two globose whorls sculptured with seven regularly spaced rounded spiral ridges abruptly marked off from post-nuclear whorls. Spire tall, about 1 ¾ times height of aperture. Outline of whorls convex. First and second post-nuclear whorls sculptured with three evenly spaced strong rounded spiral ridges, interspaces a little wider than width of ridges. First spiral at about two-thirds height of whorl, leaving a flat sloping shoulder between upper suture and uppermost spiral ridge. Third spiral near lower suture. On the penultimate a fourth spiral suddenly makes its appearance above the uppermost spiral of the early whorls, developing over the body-whorl until it almost equals the strength of the other spirals. On the body-
whorl there are seven spirals, one in line with the lower suture, four above and two below. The surface between the spiral ridges is crowded with close vertical microscopic growth-striae. Aperture sub-circular. Peristome simple, continuous, sinuous, thin, not variced or internally duplicated. Outer lip slightly protractive and effuse below, continuous over parietal whorl and pillar as a thin callus, separated from base by a distinct groove. Pillar rounded and spirally flexed. Base smooth below lowest spiral. Colour pure-white.
Height, 2.2 mm.; diameter, 1.05 mm.
Holotype presented to Auckland Museum.
Habitat, 60 fathoms off Poor Knights Islands. (Type) (dredged, Captain J. Bollons); off Little Barrier Island (dredged, Captain J. Bollons).
From the Australian wilsonensis the New Zealand species differs in having fewer spiral ridges.
The species is named in honour of Dr. H. J. Finlay as a small tribute to his fine work on New Zealand molluscan systematics.
Genus Icuncula Iredale, 1924.
Type Cingulina torcularis Ten. Woods.
Icuncula terebra n. sp. (Fig. 8).
Shell small, fragile, tall and slender, sculptured with strong spiral ridges. Whorls 6, including a large smooth protoconch of two convex whorls. Spire tall, about 2 ¼ times height of aperture, outline of whorls strongly convex. All post-nuclear whorls sculptured with prominently raised narrow spiral ridges, three on first post-nuclear whorl and a weak fourth just above lower suture on next whorl, which becomes stronger over the body-whorl making four strong spirals above the aperture. On the body-whorl a fifth spiral proceeds from the lower suture and is followed below by a sixth spiral less prominent than those above. The lower part of the base is smooth with exception of a slight ridge bordering umbilical cleft. Aperture large, ovate. Peristome discontinuous, thin, outer lip dentated by the spiral ridges. Basal lip dilated, thin, merged above into an obliquely arcuate columella, separated from the base by a narrow umbilical cleft, the actual perforation being obscured by the overhanging upper part of the columella. Colour pure-white.
Height, 2.3 mm.; diameter, 0.8 mm.
Holotype in author's collection.
Habitat, off Poor Knights Islands in 60 fathoms (dredged, Captain J. Bollons per A. Hamilton collection).
This is the most slender species of the genus, consequently the umbilicus is almost closed, otherwise it is a typical member of the genus.
Genus Seilarex Iredale 1924.
Type Seila attenuata Hedley.
Seilarex exaltatus n. sp. (Fig. 3).
Shell small, very tall, slender and gently tapering. Whorls 12, including a typical polygyrate protoconch of 4 whorls; apex smooth,
remaining whorls with a central rounded keel and crossed by close, moderately strong, slightly obliquely-retractive axial ribs. Spire tall, about 4½ times height of aperture plus canal. Outline of whorls strongly convex. All post-nuclear whorls sculptured with five strong rounded, raised, regularly spaced spiral cords, uppermost one immediately below upper suture, lowest one immediately above lower suture, third one at the middle. The whole crossed by regular, vertical, low, fold-like axials, about 15 per whorl, producing weak nodulous swellings where they cross the spirals and cutting up the surface into rectangular interspaces. The whole surface is crowded with microscopic dense axial growth striae. Base smooth, concave, with a single small raised spiral thread midway between lowest sutural cord and the pillar. Aperture sub-quadrate with a short, narrow, straight, anterior canal. Peristome discontinuous, thin and sharp. Pillar vertical, produced to a sharp point below, slightly flexed and margined on the inner side by a narrow glaze. Colour pale buff, protoconch reddish-brown.
Height, 4.5 mm.; diameter, 1 mm.
Holotype in author's collection.
Habitat, Tryphena Bay in 5–6 fathoms, Great Barrier Island, N.Z. (A.W.B.P., Jan., 1924) (type). Dredged off Sunday Island, Kermadec Islands (R. S. Bell), Auckland Museum collection.
This makes the first record of the genus in New Zealand waters and also adds a genus and a species to the Kermadec fauna. Kermadec specimens differ from the New Zealand holotype in colour only, the pillar being tinted light reddish-brown and the post-nuclear whorls sparsely spattered with the same colour. The New Zealand shell however has the appearance of being slightly bleached, which may account for the absence of colour markings.
Genus Altispecula n. gen.
Type Cerithiopsis geniculosus Hedley.
The genus is founded on a South Australian deep water shell (see Hedley Zool. Results F.I.S. “Endeavour,” part 1, p. 110, 1911) characterized by a tall narrow gently tapering shell, strongly axially ribbed but with obsolete spiral sculpture. Readily distinguished from the usual clathrate or strongly spirally ribbed “Cerithiopsis” like shells, the sculpture being more like that of Turbonilla. The protoconch consists of two smooth convex whorls.
In Specula Finlay 1926, the protoconch is few-whorled, smooth and rounded but the sculpture of the succeeding whorls consists of strong spirals rendered clathrate by regular axials.
Altispecula elegantula n. sp. (Figs. 11 and 12).
Shell small, tall and slender, many-whorled and closely coiled. Whorls probably 18. Protoconch damaged, showing about one and a quarter smooth convex whorls. Sculpture consisting of strong rounded axial ribs, obliquely inclined and parallel to the slope of the left outline of spire whorls. There are twelve axials on the body-whorl. A single low flat-topped spiral thread bridges the interspaces of the ribs at the middle of all the post-nuclear whorls but does not cross the
axials. The whole surface between the axials is microscopically reticulated by fine and close axial and spiral striae. Spire very tall about 7 times height of aperture. Outline of spire whorls moderately and evenly convex. Suture impressed, undulating. Body-whorl with the basal area separated by a rounded spiral ridge proceeding from lower suture. The axial ribs are suddenly terminated by this ridge leaving the intercostal spaces squarely excavated. The surface of the base is minutely reticulated similar to the interspaces. A small inconspicuous spiral cord encircles the pillar between basal ridge and canal. Aperture subpyriform with anterior canal short, open and broad. Peristome discontinuous. Inner lip as a broad thin glaze-over parietal wall and pillar, which is vertical about the middle, flexed to the left and produced to a sharp point below. Colour dull-white (dead shell).
Height, 7.8 mm. (about 8 mm. complete); diameter, 1.6 mm.
Holotype and one imperfect paratype in author's collection.
Habitat, off Poor Knights Islands in 60 fathoms. N.Z. (dredged by Captain J. Bollons per A. Hamilton collection).
This shell differs from the genotype in the presence of the central spiral thread.
Genus Joculator Hedley, 1909.
Type Cerithiopsis ridicula Watson.
Joculator caelata n. sp. (Fig. 19).
Shell minute, clathrate, elongate-conical, thin but solid. Whorls 7½, including a typical polygyrate protoconch of 3½ smooth convex whorls. Spire whorls sculptured with three strong raised flat-topped spiral cords, the upper one slightly smaller than the lower two. These are crossed by moderately strong rounded axials, dividing the interspaces of the spirals into rectangular spaces and producing rounded nodules at the points of intersection. Suture impressed, bordered above by a rounded thread, becoming stronger over body-whorl and separating the sculptured upper portion from the smooth base. Body-whorl with three main spirals as in spire whorls. Base smooth, rather flat, concave towards pillar which is slightly obliquely flexed. Aperture quadrate with a poorly developed anterior canal. Peristome discontinuous thin and sharp. Spire tall, about 3½ times height of aperture. Colour uniformly pale buff.
Height, 2 mm.; diameter, 0.95 mm.
Holotype presented to the Auckland Museum. Paratypes in author's collection.
Habitat, Mangonui Heads in 6 fathoms (type) (dredged by Mr. W. La Roche, 1922); Three Kings Islands in 98 fathoms (one juvenile specimen in the collection of Miss M. K. Mestayer, Wellington).
This shell is not closely related to any known species and makes: the first definite record for the genus in New Zealand. Odhner's Cerithiopsis dirempta has been referred to this genus by Finlay but only provisionally as the protoconch is not known.
Genus Zebittium Finlay, 1926.
Type Cerithium exilis Hutton.
Zebittium editum n. sp. (Fig. 15).
Shell small, elongated, spirally ribbed with narrow interspaces. Whorls 9, including a small smooth dome-shaped protoconch of one whorl. Spire high, about three times height of aperture. First post-nuclear whorl with two prominent spiral cords and second with the addition of a spiral thread at lower suture. The spiral cords are situated on the lower part of each whorl. On the third post-nuclear whorl two smaller cords appear on the upper part of the whorl and increase to three on the fourth whorl. The main cords gradually become stronger and two small interstitial threads appear, one above the lower main cord and the other between it and the sutural thread. The fifth post-nuclear whorl has four moderately strong cords between the upper main cord and the upper suture, an interstitial cord between the two main cords and another between lower main cord and sutural thread. On the body-whorl two additional strong cords appear immediately below lower suture and serve to mark off the base. The base is smooth above but sculptured around the pillar with five closely spaced flat-topped cords. All the whorls with the exception of protoconch and first post-nuclear whorl are crossed by moderately strong fold-like axial costae, more prominent on the early whorls. These form slight rectangular shaped swellings where they are crossed by the main spiral cords. Aperture ovate, slightly channelled above, broadly rounded below and slightly excavated against the pillar in the form of a simple narrowly rounded anterior canal. Peristome discontinuous. Outer lip thin and sharp, sinuous, a broad shallow depression above and slightly protractive below.
Inner lip as a narrow moderately heavy callus extending from the suture right to base of pillar. Colour light brownish-buff.
Height, 6 mm.; diameter, 1.9 mm.
Holotype presented to the Auckland Museum; paratypes in author's collection.
Habitat, off Poor Knights Islands in 60 fathoms, N.Z. (dredged by Captain J. Bollons, per A. Hamilton collection).
This species differs from Z. exile (Hutton) in sculpture and height of spire relative to that of the aperture.
Genus Pliciscala de Boury, 1887.
Subgenus Nodiscala de Boury, 1890.
Type (by original designation) Scalaria bicarinata Sowerby.
Pliciscala (Nodiscala) ahiparana n. sp. (Fig. 10).
Shell of moderate size, thick and solid with a tall spire. Whorls 8, protoconch missing. All whorls finely sculptured with close spiral striations, 9 on second whorl increasing to about 48 on the body-whorl, crossed by a dense mass of fine, slightly obliquely-retractive axial striae. The interspaces are pitted, giving a minutely punctate effect to the whole surface. The first four whorls show rather prominent
fold-like axials, about ten per whorl, becoming slightly nodulous towards the middle. The succeeding three whorls have faint broad axial folds but without nodules. The body-whorl is conspicuously bi-angulate. The lower angle proceeds from the suture and the upper one is situated a little nearer to the aperture than to the upper suture. Both angles are produced at regular intervals into prominent rounded nodules, eight on the upper angle and five on the lower. Base slightly concave between lower angle and pillar. In addition to the outer lip there are two varices on the fourth whorl separated by a little more than half a whorl. Height of spire about three times that of aperture. The outline of the spire whorls is moderately convex with a slight bulge below the middle. Suture prominently lobed and pitted. Aperture obliquely sub-circular. Peristome continuous, smooth, thick and rounded, margined by the pillar and a large, rounded, expanded and thickened flange running from the upper suture right round the base where it becomes fused with the base of the pillar. This flange is marked off from the peristome by a deep groove and is sculptured with close radiating striae. Colour dull-white.
Height, 7 mm.; diameter, 2.5 mm.
Holotype in author's collection.
Habitat, 70 fathoms off Ahipara, N.Z. (dredged by Captain J. Bollons, per A. Hamilton collection).
This species is apparently very close to the genotype so far as can be judged from available descriptions. Tryon's (1887, p. 82) description of bicarinata reads—“Subcylindrical, whitish, narrow, very minutely cancellated, with two spiral ribs on the body-whorl. Suture pitted. Length, 18 mm.” Dall (1889, p. 321), in treating bicarinata as a variety of hellenica Forbes, gave the following note— “In the variety bicarinata the carinae are present and very strong but not nodose on the last whorl; from the figure the ribs would seem to be wholly absent, but the suture is conspicuously punctate. Reeve's figure in the Iconica looks as if the type was a worn or beach specimen.”
P. (Nodiscala) ahiparana n. sp. differs from the genotype in its much smaller adult size (both bicarinata and ahiparana appearing to have about the same number of whorls) and in the presence of strong nodules on the carinae of the body-whorl and on the early spire-whorls.
Genus Liratilia Finlay, 1926.
Type Daphnella conquisita Suter.
Liratilia compta n. sp. (Fig. 9).
Shell small, fusiform, spirally ribbed. Whorls 5, including a large conical protoconch of two smooth convex whorls, abruptly marked off from the post-nuclear whorls. First post-nuclear whorl and penultimate with three strong rounded spiral cords, the lower one bordering the lower suture and the upper one at a little over one-third the height of whorl from upper suture. Interspaces about twice the width of the cords. The body-whorl has twelve cords, three above
the aperture and nine below, the lower five on the neck of the canal. Suture impressed, bordered immediately below by a moderately broad flat fold. The whole surface crossed by dense microscopic vertical axial growth-striae. Aperture narrow, elongated, sides nearly parallel, merging below into a truncated open canal. Outer lip thin, specimen not quite adult. Inner lip moderately spread as a thin glaze. Columella sinuous, vertical in the middle, obliquely flexed below and strengthened by an inconspicuous fold. Height of spire slightly greater than height of aperture plus canal. Colour pale buff zoned with three bands of darker buff, one occupying the space between upper suture and upper spiral cord, another between the second and third spiral cords and the third band between the fifth and sixth cords on the base. Protoconch pinkish-brown and the cords regularly marked with squarish reddish-brown dots.
Height, 4.7 mm.; diameter, 2.2 mm.
Holotype in author's collection.
Habitat, Taupo Bay, Whangaroa (collected by Mr. W. La Roche).
Differs from the three known species in the presence of a colour pattern and in the fewer and stronger spiral cords.
Dall, W. H., 1899. Bulletin of the Museum of Comparative Zoology at Harvard College, vol. 43.
Finlay, H. J., 1926. New Shells from New Zealand Tertiary Beds, pt. 2. Trans. N.Z. Inst., vol. 56.
—— 1926a. A Further Commentary on New Zealand Molluscan Systematics. Trans. N.Z. Inst., vol. 57.
Iredale, T., 1924. Results from Roy Bell's Molluscan Collections. Proc. Linn. Soc., N.S.W., vol. 49.
Powell, A. W. B., 1926. Mollusca from 100 fathoms off Lyttelton, with descriptions of Four New Species, and also a New Pliocene Fossil. Records Canterbury Museum, vol. 3, pt. 1, pp. 43–50.
—— 1927. Deep-water Mollusca from South-west Otago with descriptions of 2 New Genera and 22 New Species. Records Canterbury Museum, vol. 3, pt. 2, pp. 113–124.
Tryon, George W., 1887. Manual of Conchology, vol. 9.