New Zealand Fossil and Recent Cardiidae (Mollusca).
[Read before Wellington Branch, July 13, 1944; received by the Editor, July 14, 1944; issued separately, December, 1944.]
In New Zealand, as in most places, the generic name Cardium has always been used in a very wide sense, and poorly preserved fossils are likely to require its continued use. For those species however, of which we know adequate details of sculpture and hinge, more restricted generic grouping must be used if we are to obtain from them the stratigraphic and distributional evidence that they offer. The now generally accepted type of Cardium, the Recent Indo-Pacific C. costatum Linné (designated by Children, 1823) has strong, high, sharp ribs. No relatives at all close are known from New Zealand, so the use of the genus here can only be in a family sense.
Of the two Upper Cretaceous species figured by Woods (1917, plate 18, figs. 3, 4, and 5) as Cardium spp., the original of fig. 3 must still remain thus vaguely designated, little further evidence having been found. The specimens of figs. 4 and 5, however, belong to Ethmocardium. The other Cretaceous species are all related to Lahilia and have been classed in a separate sub-family Lahilliinae (Fin. and Marw., 1937).
In her most useful summary of the Cardiidae, Dr. Myra Keen (1937, p. 13) excluded Lahillia from the family, suggesting its relationship to Thetironia Stoliczka. Much uncertainty has prevailed as to the family affinities of Thetironia, the general tendency being to put it in the Veneridae. This was done mostly without a true knowledge of the hinge, as is shown by Dall's statement (1903, p. 1283) that it had three cardinal teeth. Woods (1907, p. 165) has since clearly shown by his description and figures of the genotype that the cardinal teeth are on the Cardiid pattern, even to the cycloid arrangement.
The Lahillia hinge is so like the Cardiid one (lacking only the anterior lateral tooth) that relationship is certainly closer to the Cardiidae than to any other family that has yet been proposed. Whether Lahillia should remain in the Cardiidae or not is merely a question of how comprehensive a family should be. The subfamily Lahilliinae was proposed so as to draw attention to the differences from the Cardiidae and at the same time not lose sight of the affinities to it. The same effect is got by recognising the family Lahilliidae as a member of the super-family Cardiacea. Although Cardiids are so numerous, and so varied in many of their characters, their hinges are very conservative. Consequently the complete absence of an anterior lateral in Lahillia may be taken as of greater importance than usual for such a character. This, together with the tendency to sinuation in the pallial line, and the lack of sculpture or of radial structure in the shell (including absence of marginal crenulations) induces the writer, following Frizzel's (1936) treatment of the Veneridae, to elevate the Lahilliinae to family rank as the Lahilliidae of the super-family Cardiacea.
The Cardiids of New Zealand fall into six distinct groups, easily distinguished, and without intergrading or intermediate members.
Key to Genera and Subgenera.
|A. Small, generally well under 1 inch diameter.|
|a. Sculpture of fine radials, posterior area well differentiated||(Pratulum)|
|b. Sculpture of coarse radials, interior with radial rows of pits||Ethmocardium|
|B. Large, over 2 inch diameter.|
|a. Sculpture of posterior area not differentiated, whole surface strongly ribbed|
|1. Longitudinally oval; ribs tuberculate, especially antero-ventrally.||Maoricardium|
|2. High oval; ribs not tuberculate||(Ovicardium)|
|b. Sculpture of posterior area strongly differentiated.|
|1. Almost smooth medially, concentrically waved antero-ventrally, posterior area finely radially ridged||Varicardium|
|2. Strongly ridged by smooth rounded ribs, those on posterior area lower and bevelled with linear interstices||Hedecardium|
The following table shows the current classification of the species, also the revised classification:—
|Current Classification.||Revised Classification.|
|Cardium brunneri Hector||Hedecardium brunneri (Hector)|
|coxi Hector||indeterminable, probably distorted|
|facetum Suter||Venericardia sp. indet.|
|gudexi Laws||Maoricardium gudexi (Laws)|
|oneroaensis Powell||Maoricardium oneroaense (Pow.)|
|spatiosum Hutton||Maoricardium spatiosum (Hutt.)|
|strangi Laws||Maoricardium strangi (Laws)|
|subcordatum Suter||Hedecardium subcordatum (Suter)|
|cantuariense Laws||Hedecardium cantuariense (Laws)|
|greyi (Hutton)||Hedecardium greyi (Hutt.)|
|waitakiense Suter||Hedecardium waitakiense (Suter)|
|dolichum Suter||Procardia dolicha (Suter)|
|maorinum Suter||Procardia dolicha (Suter)|
|priscum Suter||Hedecardium brunneri (Hector)|
|Cardium sp. 1, Woods||Cardium sp.|
|Cardium sp. 2, Woods||Ethmocardium woodsi n.sp.|
|alatum Suter||Varicardium patulum (Hutt.)|
|patulum (Hutton)||Varicardium patulum (Hutt.)|
|serum (Hutton)||Varicardium serum (Hutt.)|
|diversum Marwick||Nemocardium (Pratulum) diversum Marw.|
|finlayi Bartrum and Powell||Nemocardium (Pratulum) finlayi Bart. and Pow.|
|pulchellum (Gray)||Nemocardium (Pratulum) pulchellum (Gray)|
|semitectum Marwick||Nemocardium (Pratulum) semitectum Marw.|
As will be seen from the list, the shells that have generally been classed under Cardium s. str. are those of the Cardium spatiosum group for which the new genus Maoricardium is proposed. They are huge, thick, veneriform shells with strong, tuberculate ribs, related to the Boreal Cerastoderma and Clinocardium. They are first known from the Duntroonian (Upper Oligocene).
Trachycardium was introduced into New Zealand systematics, on Dall's advice, by Suter (1907) when he described C. waitakiense and the usage has been fairly consistently maintained by subsequent workers. The shells, however, though having the right cardinals cemented together, are very distant from isocardia L., the type of Trachycardium, both in shape and sculpture, particularly in the differentiation of the posterior area; consequently the new genus Hedecardium has been set up. The line is rather commonly represented in New Zealand from the Bortonian (middle Eocene) to the Awamoan (lower Miocene) and the type of sculpture appears to be unique. The group is probably endemic and may have descended from an Upper Cretaceous ancestor which has not yet been discovered. Of overseas species, the Patagonian C. philippii shows some resemblance. It has similar, strong, smooth radials, but the anterior ones are differentiated and the posterior ones slightly tuberculate in a different manner. The Victorian C. pseudomagnum McCoy may also be related.
Much closer relatives to the Trachycardium stock, however, are present in the New Zealand Tertiary. Ovicardium certainly has similar shape and type of ribbing and must have a common origin with Trachycardium and the Australian Regozara. Trachycardium senu lato is very widely and strongly represented in the Indo Pacific region.
Two quite distinct groups were classed by Suter under Nemocardium (as a subgenus of Protocardia); first, the small, thin, Recent and Pliocene pulchellum, since classed in Pratulum Iredale, and second, the much larger species such as alata and sera. Stewart (1930, p. 274) has discussed the Protocardia-Nemocardium-Pratulum groups and given good reasons for generically separating Nemocardium from Protocardia, but he left the relationship of Pratulum to Nemocardium an open question.
The Pratulum line has had a long history in New Zealand, evidence for continuity since the Wangaloan (Danian) being very good. The pre-Pliocene shells do not have the transverse sculpture, including tubercles on the posterior ribs, so well developed as in the Pliocene and Recent pulchellum or the Recent Australian genotype thetidis Hedley. The Chatham Island Tertiary diversum is, perhaps. closer to Nemocardium than to Pratulum, for it has the main part of the disc almost smooth, though it lacks tubercles on the posterior ribs. It is, in fact, difficult to decide which of the two groups should be used for several of the species. The Japanese Pliocene and Recent modestum Adams and Reeve, for instance, has the radials of the disc better defined than those of diversum, and no posterior tubercles, yet geographically it would be considered a Nemocardium, which has been recorded from the China Sea in N. bechei (Ad. and Rve.). In
view of their very close resemblance it seems advisable to retain Pratulum as a subgenus of Nemocardium.
For the group of large shells classed by Suter in Nemocardium, the new genus Varicardium is now proposed. The strong, concentric ridges developed antero-ventrally may be an archaic feature, but they are much stronger, yet more irregular, than the concentrics of the Cretaceous Protocardia. Only three species are known, and all records of these are from mid-Tertiary beds, Upper Oligocene to mid-Miocene. No close relatives are known from outside New Zealand, so, like Maoricardium and Hedecardium, the genus is probably endemic and its absence from the lower Tertiary due to the imperfect record.
Suter's use of Fragum cannot be defended. One of the species, priscum, is based on a distorted internal cast probably a Hedecardium. The other two species are based on much distorted largely decorticated casts here identified as Procardia Meek.
|“Cardium” sp. 1 Woods||—|
The writer is indebted to Miss K. S. Murray for the clear, accurate drawings, and to Captain D. H. K. Ross for the fine photographs of Trachycardium.
For the loan of specimens for this revision he wishes sincerely to thank Dr R. S. Allan and Mr A. W. B. Powell.
The holotypes of new species described below are in the collection of the New Zealand Geological Survey.
Genus Ethmocardium White.
1880. Proc. U.S. Nat. Mus. 2: 292.
Genotype (o.d.): Cardium whitei Dall. Upper Cret., Colorado and Montana. Figured (as speciosum M. & H.) by Meek, U.S.G.S. Territ., vol. ix, Pl. 37, Figs. 4, a, b, c.
Ethmocardium woodsi n.sp. (Plate 36, Fig. 21.)
1917. Cardium sp. 2. Woods, N.Z. Geol. Surv. Pal. Bull. 4: 33, Pl. 18, Figs. 4, 5.
The tubercles that Woods drew attention to and figured are a diagnostic feature. They are cylindrical, flat-topped projections of the matrix on the surface of the internal cast and represent small pits arranged in radial rows on the interior of the shell within the pallial line. They are not the internal reflections of tubercles, on the main radials at all events, because the rows are opposite the rib interstices of the exterior. On the holotype the pits are absent from much of the anterior part of the disc, but on the paratype (Woods, Fig. 4) there are three additional rows anteriorly.
Dall (1900, pp. 1071, 1072, footnote) has discussed a similar condition that characterises the genus Ethmocardium, based on the West American, Upper Cretaceous Cardium whitei Dall and represented in the Turonian of north-west France by C. alternata d'Orb. A further species, E. welleri Stephenson (1941, p. 195), has been described from the Navarro (Maestrichtian) of Texas.
Woods did not consider the New Zealand material worth naming, but the restricted generic identification that is here made alters the position, so the specific name woodsi is proposed. There are only about 25 radial ribs, which are consequently much broader than those of either of the American species.
The hinge of Ethmocardium does not seem to have been observed.
Height, 12 mm.; length, 12 mm.; inflation (1 valve), 4 mm.
Locality: G.S. 589. Selwyn Rapids. Piripauan, Upper Cretaceous.
Cardium sp. 1, Woods.
1917. N.Z.G.S. Pal. Bull. 4: 33, Pl. 18, Figs. 3a, b.
Locality: G.S. 13. Calcareous conglomerate, Amuri Bluff, Piripauan.
Only the single cast figured by Woods is known. Although the umbo appears to be opisthogyrous, the hinge, as far as can be deter-
mined, is on a Cardiid pattern. It well may be that the internal cast does not show the true twist of the umbones. Retention under Cardium sensu lato seems to be the best course for the present.
Genus Hedecardium nov.
Shell moderate to very large, subcircular, subequilateral to oblique, inflated, in substance relatively thin. Lunule lanceolate, smooth, raised on hinge margin over cardinals. Escutcheon on large species. Sculpture of numerous, strong, generally smooth, radial ribs, with well defined, generally narrower interstices, the ribs semicircular to subquadangular in cross section, interstices with close, waved, concentric ridges. Posterior area sharply differentiated, radials low, bevelled, with linear interstices that in youth bear small denticles. Hinge-line narrow, right cardinals welded together full length, posterior one long, slender, upcurved; anterior one short, bluntly conic; left hinge with anterior cardinal long, slender, pointed; posterior short, blunt, situated considerably higher on the hinge; laterals of moderate size, rather narrow, sharply pointed. Muscle impressions relatively small, pallial line broad, bluntly angled postero-ventrally thence ascending almost vertically and somewhat sinuously, distant from posterior margin, to meet posterior adductor at its antero-ventral corner.
Genotype: Cardium waitakiense Suter, Oligocene.
This line persisted in New Zealand from Bortonian (mid-Eocene) to a little later than Awamoan (low-Miocene) and produced shells as large as 140 × 150 mm. In general shape, Hedecardium is like Vepricardium Iredale; but the sculpture is different, the posterior area much more differentiated, the adductor scars considerably smaller and the posterior part of the pallial line set further in from the margin.
The later species, greyi and cantuariense, besides being larger than the earlier species have a wide posterior gape. This raises the question whether they are really of the same lineage as Hedecardium s.str. It is possible that they represent an invasion of a related but distinct stock. However, since all other characters agree closely, it seems best to regard the gape as having developed from waitakiense.
The Victorian Miocene C. pseudomagnum McCoy is not unlike some of the later, large species of Hedecardium; but it is not clear whether the posterior area is similar. According to McCoy pseudomagnum is not close to any other Australian species.
Few changes are seen in the characters of the group throughout its known range. There is a progressive increase in size and some tendency towards flattening and widening of the ribs. The posterior area is quite different in appearance because its ribs differ from those on the rest of the shell. For convenience of description the ribs are here termed “posterior” and “main.” The main ribs can be divided again into “anterior” and “medial.” The anterior ones are more rounded and have wider interstices than the medial, but there is no sharp division.
Key to Species of Hedecardium.
|A. Adult under 75 mm. long, posterior margin closed.|
|(I) Medial ribs equal to or narrower than interstices.|
|(a) Adult under 40 mm. long||brunneri|
|(b) Adult over 50 mm. long|
|(1) Main ribs numbering 40–47||waitakiense|
|(2) Main ribs numbering 37||olssoni|
|(II) Medial ribs much broader than interstices||subcordatum|
|B. Adult over 75 mm. long, posterior margin gaping.|
|(1) Medial ribs about equal to interstices||greyi|
|(2) Medial ribs much broader than interstices||cantuariense|
Hedecardium brunneri (Hector). (Plate 36, Figs. 9, 11.)
1886. Cardium brunneri Hector, Outline N.Z. Geol. p. 58. f. 20, no. 5.
1915. Suter, Alph. Handlist: 6.
1917. Cardium (Fragum) priscum Suter. N.Z.G.S. Pal. Bull. 5, p. 77, pl. 10, fig. 6.
Shell somewhat small, subcircular, beaks fairly prominent, moderately inflated. Sculpture of about 40 strong, rounded, main radial ribs with deep interstices of about the same width; posterior area probably with about 12 flat ribs with linear interstices.
Height, 30 mm.; length, 34 mm.; inflation (1 valve) 11 mm.
The shell is somewhat distorted. originally it was more nearly circular.
Localities: G.S. 29, Island Sandstone, Brunnerton (type). G.S. 45, Sandstone below limestone, St. Kilda, Brighton, West Coast. G.S. 1593, Millerton Colliery, West Coast, 150 feet above coal, Kaiata Mudstone. G.S. 27, Ten Mile, Greymouth, Island Sandstone. Near Kiwi Compressor. Denniston Colliery, West Coast, Kaiata Mudstone. G.S. 578, Greensand below limestone, Kakahu River. G.S. 480, Concretionary sandstone below greensand Waihao River. G.S. 176, Sandstone above coal beds, Black Point, North Otago. G.S. 2119, Concretions in silts, Green Valley, Waihemo S.D. G.S. 41, “Black Limestone, Tokomairiro,” Otago.
This species, frequently mentioned in the early discussions of West Coast stratigraphy, has not previously been described, its only claim to legality being a crude figure and a good locality. These are quite sufficient for recognition, within somewhat wide limits, but better specimens from the type locality may, some day, be found. A specimen from G.S. 29, Brunner Mine, from beds overlying the coal has been chosen as lectotype (Pl. 36, Fig. 9). It is accompanied by an old Colonial Museum label and presumably was identified as C. brunneri by Hector; it probably represents original syntype material.
Hedecardium waitakiense (Suter). (Pl. 35, Figs. 1, 2, 5.)
1907. Cardium (Trachycardium) waitakiense Suter, Proc. Mal. Soc., vol. vii, p. 209, pl. 18, fig. 6.
1915. Suter. N.Z.G.S. Pal. Bull. 3, p. 59, pl. 8, fig. 20.
Suter described this species from the fragment of a right hinge. A complete specimen of each valve as well as a number of hinge fragments were collected by the writer from the type locality, so that Suter's description can now be amplified. The ribs number about 40; they are flattened on top and separated by regularly rounded interspaces. On about juvenile half of shell medial ribs are wider
than interspaces, but on adult, interspaces are wider than ribs; flattened tops of main ribs are smooth and glossy, but interspaces bear close, fairly regular but somewhat undulating concentric growth-ridges. Posterior, which is glossy throughout, bears about 14 of the peculiarly differentiated, flattish ribs. In juvenile these ribs are not raised and several of the anterior ones bear a shallow longitudinal furrow; they are separated by linear grooves set with small tubercles which are really developed on anterior side of each rib. In adult, ribs become raised, at first strongly bevelled, steep face anterior, but finally more rounded, and there are no tubercles.
Localities: “Greensand, Wharekuri” (type); G.S. 476, Kekenodon Beds, Wharekuri; G.S. 1821, north bank, Waitaki River, opposite Wharekuri; G.S. 1913, Shell Gully, Kelly's farm, Chatton; G.S. 2108, Greensand, Te Raumaku School, 2 ½ miles west of Otorohanga; G.S. 526, 1027, Okoke, Pirongia S.D. (Duntroonian).
Shell of moderate size, like waitakiense but differing in having only 37 instead of from 40–47 ribs. Main ribs noticeably higher and broader than those of waitakiense, but relationship of rib to interstice on different parts of disc about the same Shell shape also differs, posterior end being more truncate and whole shell more stoutly built.
Height, 61.5 mm.; length, 62 mm.; inflation, 23 mm.
Locality: G.S. 1913, Shell Gully, Kelly's Farm, Chatton (Duntroonian)
Although this shell is of the same age as waitakiense, the fewer triangular ribs and wide interstices justify separation. The number of ribs is much the same as that of subcordatum, but the wide interspaces between the sharply ridged ribs characterise olssoni. The species is named in honour of Mr Axel A. Olsson, of Gloversville, New York, with whom the writer spent a most pleasant collecting trip.
Hedecardium subcordatum (Suter).
1917. Cardium subcordatum Suter, N.Z.G.S. Pal. Bull. 5, p. 77, pl. 10, fig. 7.
Only the holotype of this species is known. It has about 37 main ribs and 12 posterior ones. The main ribs have flattened tops and are about twice as wide as the interstices.
Locality: Suter gave in his original description “Shell-bed at base of ‘Pareora’ beds, junction of Porter and Thomas Rivers, Trelissick Basin” and the accompanying label says “Trelissick Basin B.” (See Pal. Bull. 8, p. 50.) A good deal of matrix adheres to the specimen and since it is tuffaceous, the locality is wrong. The tuff consists of greenish grey much weathered volcanic fragments set in a good deal of secondary calcite, and is the same in appearance as the tuffs between limestones at the junction of the Porter and Thomas Rivers. Also adhering to the holotype, and shown in the original photo, is a specimen of Modiolaria elongata (Hutton), a species occurring commonly at this locality and not in the shell bed overlying the upper limestone. It is quite clear then that the true locality is “Tuffs between limestones, junction of Porter and Thomas Rivers.” The faunules of this bed, both Foraminiferal
(H. J. F.) and Molluscan are of unusual facies, so correlation is not obvious, but probabilities indicate Duntroonian.
Hedecardium greyi (Hutton). (Pl. 35, Fig. 4.)
1873. Cardium greyi Hutt. Cat. Tert. Moll., p. 23.
1915. Suter, N.Z.G.S. Pal. Bull. 3, p. 59, pl. l, fig. 3.
1929. C. (Trachycardium) greyi Pow. & Bart., Trans. N.Z. Inst., vol. lx, p. 408, figs, 35, 36, 39, 40.
It is doubtful whether cantuariense can be maintained as a distinct species from greyi. Probably the question can be definitely settled only by statistical methods which must wait on the accumulation of numbers of specimens. Members of the group occur at a number of localities from the Waitakian to somewhat above the Awamoan. They are very large shells, some exceptionally large, differing from the earlier species of Hedecardium not only in greater size and shell-thickness, but also in having a pronounced posterior gape. As shown by the growth lines, this gape develops at an early stage, well before half the adult diameter is reached.
Kyeburn shells have fairly well-rounded ribs throughout, as also do the fragments from Otiake. Law's figures of cantuariense on the other hand, show considerable flattening of the adult medial ribs, accompanied by a relative narrowing of the interstices. A fine left valve from Ardgowan has flattened ribs like cantuariense, but it is smaller (79 × 80 × 35 mm.) yet is more inflated and regularly globose than usual for members of the group which generally become oblique with maturity. Oneroa shells seem to be somewhat variable in medial rib-width as also are the Mangapakeha ones which, incidentally, measure up to 145 × 150 × 60 mm. The Mokau and Clifden shells seen are poorly preserved, but in general their medial ribs tend to be flattened. From this it appears that flattening of the medial ribs and relative narrowing of the interstices may perhaps be used to separate stratigraphic species.
Hedecardium cantuariense (Laws). (Pl. 35, Fig. 3.)
For remarks see previous species.
Locality: Sutherlands, South Canterbury (type); G.S. 1985, shell bed, Ardgowan, North Otago.
Genus Maoricardium nov.
Shell very large, thick, umbos strongly prosogyrous, at anterior third or fourth. Lunule with raised margin; escutcheon not defined. Sculpture of numerous strong radials bearing blunt. cup-shaped tubercles, especially anteriorly and ventrally. Hinge long, moderately wide cardinals; left anterior cardinal short conical, left posterior cardinal long, not so high, almost horizontal, close to ligamental nymph; left anterior lateral high and strong, without socket for right anterior; left posterior lateral, weak; right posterior cardinal very large, right anterior also relatively large; laterals strong. Ligamental nymphs long and very high.
Genotype: Cardium spatiosum Hutton. Pliocene.
This lineage of Cardiidae was relatively common in New Zealand in the middle and later Tertiary. Four species have been described, C. strangi Laws, Duntroonian (Oligocene), C. gudexi Laws, C. oneroaense Pow. (Miocene), and C. spatiosum Hutton (Lower Pliocene). The shells, especially of C. spatiosum grew to a
great size, a length of 150 mm. being not uncommon. No close relatives of the group appear to be known in Australia or South America, the nearest being the North Pacific Clinocardium Keen and the North Atlantic Cerastoderma (Poli) Moerch. Maoricardium differs from Clinocardium in its high ligamental nymph and in the strong, cupshaped tubercles on the ribs. From Cerastoderma it differs in its much greater size, larger right cardinals, and almost horizontal left posterior cardinal which, besides, is close to the nymph. The left posterior cardinal is weaker and nearer the dorsal margin.
Key to Species of Maoricardium.
|A. Ribs, about 50, lightly built, shape elongate subquadrate.||strangi|
|B. Ribs, about 38, heavily built.|
|I. Rib interstices narrow to linear, shape subquadrate.||gudexi|
|II. Rib interstices broad, shape elongate subquadrate||spatiosum|
|C. Ribs, about 41||oneroaense|
Maoricardium strangi (Laws).
1930. Cardium strangi Laws, Trans. N.Z. Inst., 61: 549, figs. 6, 9.
Locality: Shell Gully, Kelly's Farm, Chatton.
A second specimen, a left valve, now in the Geological Survey Collection, has been collected at the type locality by Mr Axel A. Olssen, Mr E. O. Macpherson, and the writer. This specimen is somewhat more attenuated than the holotype.
Maoricardium gudexi (Laws). (Pl. 37, Fig. 29.)
1933. Cardium gudexi Laws, Trans. N.Z. Inst., 63: 316, figs. 7, 14.
Localities: Sutherlands, South Canterbury (type); shell bed above upper limestone, lower gorge of Porter River, Trelissick Basin.
The Trelissick specimen has well developed tubercles like oneroaense, but the radials are flat. See remarks under oneroaense.
Maoricardium oneroaense (Powell).
1938. Cardium oneroaense Pow., T.R.S.N.Z., 08: 307, pl. 38, figs. 7–8.
The type of oneroaense has a few more ribs than the type of gudexi, and they are slightly more convex, the anterior tubercles are better developed, also the shell is lighter built, so that the hinge is less arched. These differences are little, if any, greater than those to be seen between individuals of M. spatiosum, and since the matrix of oneroaense is more argillaceous than that of gudexi, the differences may be due to habitat. As in the case of H. greyi and cantuariense, the true relationship of these forms can only be determined from a larger number of specimens than now available.
Locality: Oneroa, Waiheke Island.
Age: About Awamoan.
Maoricardium spatiosum (Hutton). (Pl. 37, Fig. 30.)
1873. Cardium spatiosum Hutt., Cat. Tert. Moll. 23.
1914. Suter, Pal. Bull. 2: 52, pl. 15, figs. la, b.
Localities: Waitotara (type) the precise locality has. not been determined: M. spatiosum occurs widely in Waitotaran beds and was obtained by Laws (1940, p. 37) from beds considered to be low in the Nukumaruan. This appears to be an exceptional occurrence, however, for the species is not known from the Nukumaruan else-where. Maoricardium is known from Opoitian and Taranakian beds
at several places and has generally been recorded as spatiosum. No good specimens, however, have yet been seen from beds between Awamoan and Waitotaran, so where the boundary should be drawn between spatiosum and gudexi is not known.
Genus Nemocardium Meek.
1876. Dep. Inter. Rep. U.S. Geol. Surv. Terr., vol. ix, p. 167.
Genotype (monotypy): Cardium semiasperum Desh. Eocene, Paris Basin.
Subgenus Pratulum Iredale.
1924. Proc. Linn. Soc. N.S.W., vol. xlix, p. 182.
Type (o.d.): Cardium thetidis Hedley. Recent, N.S. Wales.
The use of Nemocardium and its relation to Pratulum are discussed in the introduction to this paper.
Key to Species of (Pratulum).
|A. Main ribs weakly developed.|
|(a) Surface almost smooth, main ribs indicated by weakly incised lines.||diversum|
|(b) Ribs plainly defined, but very low||modicum|
|B. Main ribs well developed.|
|(I) Medial ribs at 10 mm. from umbo 5 per mm.|
|(a) Interstices narrow.||semitectum|
|(b) Interstices wide.||quinarium|
|(II) Medial ribs at 10 mm. from umbo 3 per mm.||pulchellum|
|(III) Medial ribs at 10 mm. from umbo 2 per mm.||finlayi|
Nemocardium (Pratulum) modicum n.sp. (Pl. 36, Figs. 17, 18.)
1937. Nemocardium (Pratulum) sp. Finlay and Marwick, N.Z.G.S. Pal. Bull. 15, p. 30. pl. 4, fig. 6.
Shell small. Main ribs, about 45, scarcely raised, broadly rounded, separated by linear interstices and crossed by numerous growth lines. Posterior ribs, about 16, very narrow, irregularly, weakly nodular, separated by wide, flat interstices, growth lines strongly marked.
Height, 6.5 mm.; length, 7 mm.; inflation, 2.6 mm.
Localities: Boulder Hill, near Dunedin, type; Wangaloa (Danian).
The sculpture though preserved on only a small part of the holotype is clearly enough shown to enable easy differentiation from other species. Consequently reconsideration of the type material seems to justify granting a name.
Nemocardium (Pratulum) semitectum Marwick.
1926. Nemocardium semitectum Marw., Trans. N.Z. Inst., vol. lvi, p. 312, pl. 72, fig. 8.
In the original description the statement about the ribbing needs correction. The diameter 22 mm. should read 12 mm., and the number of ribs should be 5 for medial ribs and 6 for anterior.
Locality: Tuffs, Lorne (Lower Kaiatan-Waiarekan).
Nemocardium (Pratulum) diversum Marwick.
1928. Nemocardium diversum Marw., Trans. N.Z. Inst., vol lviii, p. 472, fig. 85.
Locality: Tuffs, Waikaripi, Chatham Island.
The age of this species is not known, but the general affinities of the faunule accompanying it are with Eocene and Oligocene species in New Zealand.
Nemocardium (Pratulum) quinarium n.sp. (Pl. 36, Figs. 10, 16.)
Shell small. Radial ribs rounded, very fine, medials 5 per mm. at 10 mm. from umbo; main ribs, about 70; interstices well marked, nearly as wide as ribs; concentric ridges well developed, closely placed. Posterior ribs, 32; narrow and high rounded, not tuberculate, connected across wide interspaces by strong transverse ridges, not crossing radials and not corresponding in adjacent interstices.
Height, 11 mm.; length, 12 mm.; inflation, 4 mm.
Localities: G.S. 1325, roadside just east of Mangatarehu Stream, Waikohu Surv. Dist. (type); G.S. 1369, 36 chains north-west of Trig. A, Waingaromia Surv. Dist.; also many other localities in Gisborne district. (Opoitian.) Many examples also in Opoitian beds in Wairoa Subdivision.
N. quinarium can be distinguished from pulchellum not only by the finer and more numerous ribs but also by the narrow interstices and the well developed transverse bars and absence of tubercles on the posterior area.
Nemocardium (Pratulum) finlayi Bartrum and Powell.
1928. Nemocardium finlayi Bart. & Pow., Trans. N.Z. Inst., vol. lix, p. 159, fig. 48.
Localities: Kaawa (type), (Opoitian); G.S., 1560, Waihua River, Hawke's Bay (? low Waitotaran).
Nemocardium (Pratulum) pulchellum (Gray). (Pl. 36, Figs. 12, 13, 20.)
1843. Cardium pulchellum Gray, Dieffenbach's N.Z., p. 252.
1913. Protocardia (Nemocardium) pulchella (Gray): Suter, Manual, p. 1000, pl. 62, fig. 9.
Localities: Recent, New Zealand, 10–120 faths. Numerous localities in Castlecliffian, Nukumaruan and Waitotaran beds. The species has been recorded from many localities in the Tutamoe Series (Marwick, 1931, p. 77), These should not have been identified so positively as many are no more than generic identifications based on poor material. None are from the typical Tutamoe beds of Muddy Creek, but all are from the upper part of the series as then used, and are probably Taranakian and higher. N. pulchellum does not seem to go below the Waitotaran.
Genus Varicardium nov.
Shell fairly large, subcircular to suboval, subequilatcral. Lunule with raised inner margin; escutcheon narrow, deep. Sculpture: Middle of disc, when well preserved, smooth and glossy, but with very fine, concentric lines, also almost equally fine radials defined by sub-surface or very shallow lines; anterior and ventral part of disc with strong, concentric, undulating, rounded, bevelled ridges; posterior area with numerous strong, smooth, close, radial ridges. Hinge moderate to strong, laterals well developed; right valve with strong, vertical, hooked, posterior cardinal, connected to half its height with anterior, transverse cardinal which is a scarcely raised pad on thick lunular margin; left hinge with strong, vertical, anterior cardinal and very weak, oblique, curved, posterior cardinal. Valve margins dentate, those of posterior coarser.
Genotype: Varicardium patulum Hutton, Miocene.
Varicardium differs from Nemocardium in having strong concentric ridges anteriorly and ventrally, and in consistently lacking
tubercles on the posterior area. Also Varicardium is typically much larger and heavier built, though the Paris Basin Eocene N. wateleti (Desh.) is about as large as N. serum. The group is first known from about Duntroonian; it occurs fairly widely about the Awamoan and somewhat later, but it has not been found in the Taranakian.
Key to Species of Varicardium.
|A. Subcircular; length, about 80 mm.; moderate hinge.||patulum|
|B. High Oval. Rather lightly built, under 60 mm. long.|
|Restrained hinge, concentric ridges, about 1½ mm. apart.||serum|
Varicardium serum (Hutton). (Pl. 37, Figs. 26, 27.)
1873. Protocardium serum Hutt., Cat. Tert. Moll., p. 23.
1886. Protocardium serum Hector, Outline N.Z. Geol., p. 54, fig. 15, no. 13.
1914. Protocardia sera Hutt., Suter, N.Z.G.S. Pal. Bull. 2, p. 53, pl. 14, fig. 8.
1926. Nemocardium patulum (Hutt.), Finlay, T.N.Z.l., vol. lvii, p. 471.
As will be seen from the discussion under the following species, V. serum should not be synonymized with patulum, the type locality of which must be regarded as The Deans, Waipara, and from which it can be readily separated by its higher, less circular outline. The rather crude figures of Hector's Outline give a very good rendering of this difference in shape.
Localities: As shown by the peculiar matrix, Hutton's Broken River locality of his 1873 Catalogue, in most cases, is really the same as Geol. Surv. 239 (and some of 449), “Tuffs between limestones, Junction of Porter and Thomas Rivers, Trelissick Basin.” (Perhaps Duntroonian.) G.S. 2946, Clifden, zone 6a (about Awamoan).
Varicardium patulum (Hutton). (Plate 37, Figs. 24, 28, 32, 33.)
1873. Cardium patulum Hutt., Cat. Tert. Moll., p. 23.
1886. Cardium patulum Hutt., Hector, Outline N.Z. Geol., p. 54, fig. 15, no. 3.
1917. Protocardia (Nemocardium) alata Suter, N.Z.G.S. Pal. Bull. 5, p. 78, pl. 10, fig. 8.
1924. Protocardia patula (Hutt), Finlay, T.N.Z.I., 55, p. 498, ? includes sera and alata.
1926. Nemocardium patulum (Hutt), Finlay, T.N.Z.I. 57, p. 471.
When Suter (1914) revised Hutton's 1873 types, several were missing. Most of these have since been found, and among them that of Cardium patulum. The shell, which is from The Deans, Waipara, is fairly complete and proves to be easily distinguished by shape from V. serum. Unaware that Hutton's type had been recovered, Finlay designated Broken River (Lower) as the type locality of patulum. Hutton, however, gave as localities, “The Deans, Waipara; Broken River (L) ?”. By analogy with Internat. Rules, Art. 30, sect. IIe, γ, the doubtful locality is not available and the other is automatically the type. This, in addition to the existence of Hutton's original type, invalidates the Broken River designation.
Although Suter's holotype of alata is only a fragment, it is clearly conspecific with the type of patulum. Both are from the same district, Suter's specimen, collected by Thomson (1920, p. 363) from a shell bed at the base of the Main Mount Brown limestone in Weka Creek, and Hutton's from The Deans, Waipara, some three miles south along a prominent escarpment.
Localities: The Deans, Waipara (type). Lower shell bed below uppermost Mt. Brown limestone, Weka Creek. Glauconitic sandstone below shell bed, Target Gully, Oamaru. (Awamoan.) Clifden, zones 6b, 6c, 7.
Genus Trachycardium Moerch.
Genotype: C. isocardia L. Recent, West Indies.
Subgenus Ovicardium nov.
Shell large, thick, obliquely high oval, closed. Sculpture of numerous square ribs with deep interstices. Lunule slightly concave; no escutcheon. Hinge moderate; left valve with strong anterior cardinal; posterior cardinal very small, almost horizontal, having rather deep, wide groove running from below it obliquely back across hinge. Left anterior lateral (AII) very long and strong, bounded above by a deep groove extending past it towards umbo; ventrally with only weak depression for reception of A I. Posterior lateral rather small, continuing into ligamental groove behind high nymph.
Genotype: Trachycardium (Ovicardium) rossi n.sp.
This shell belongs broadly to the Trachycardium group, fairly large, high, oval shells with strong ribs. The following groups fall into this category, and their use as subgenera under Trachycardium recognises their differences yet preserves what appears to be an obvious relationship:—
Trachycardium Moerch, 1853; Phlogocardia Stewart, 1930; Mexicardia Stewart, 1930; Dallocardia Stewart, 1930; and Regozara Iredale, 1936.
Agnocardia Stewart was also proposed as a subgenus of Trachycardium in 1930, but it does not have the oval form characteristic of the groups mentioned, and may not be closely related. Regozara is an Australian group, the others all belong to the tropical and sub-tropical seas of America, some eastern, some western. Ovicardium might reasonably then, be expected to show closer agreement with Regozara than with the American subgenera, but such is by no means obvious. About the only common point of difference from Trachycardium s.str. shown by both Austral groups is the larger lateral A II, and even here there is much difference in shape, the general disposition of that of Regozara being more like that of Trachycardium. Apart from this small hinge difference, Regozara differs from Trachycardium only in details of sculpture. Ovicardium, however, differs from both and also from the other groups in several important features as well as sculpture—namely, (1) the oblique groove across the left hinge; (2) the long, deep groove above A II; (3) the concave lunule. Although we do not yet have a record of it, Ovicardium probably has existed as a separate entity since well before the Pliocene.
Trachycardium (Ovicardium) rossi n.sp. (Pl. 35, Figs. 7, 8.)
Sculpture of 51 smooth, strong, radial ribs, in general nearly rectangular in cross-section, with interstices of about equal width. Anteriorly, for about the first 5, the ribs are more rounded, closer and crossed by low, regular spaced ridges. Posterior area not strictly
defined, the more posterior ribs gradually becoming more rounded and lower. The most posterior three much broader.
Height, 102 mm.; length, 95 mm.; inflation (1 valve), 35 mm.
Localities: G.S. 1541, Te Reinga Falls, Hangarua River (type) (Waitotaran); G.S. 1244, Mangatuna Quarry, Uawa Surv. Dist.; Sandstone, Tokomaru Bay. (Opoitian.)
This species is named in honour of Captain D. H. K. Ross, formerly of the Geological Survey, to whom I owe the fine photographs of this fossil.
Trachycardium (Ovicardium) parki n.sp. (Pl. 36, Figs. 19, 22, 23.)
Shell large, high oval, well inflated. Sculpture of 40 squarish main ribs with interstices about half as wide, the rib bounding posterior area of double width; on posterior area are 8 somewhat rounded ribs with shallow interstices, the most posterior two ribs wider than others. Hinge worn but apparently without oblique groove, anterior lateral relatively small.
Height (if complete), 95 mm.; length, 90 mm.; inflation, 35 mm.
Locality: G.S. 634, shell beds, mouth of Butler's (Ototoka) Creek, Nukumaru Surv. Dist. (basal Castlecliffian).
This species is named in honour of Professor James Park, who collected it in 1886. It was listed (Park, 1887, p. 53) as Cardium multiradiatum Hutton (rightly of Sowby.).
The single specimen is fragmentary and badly worn, as are many of the shells from this locality. Indeed, some of them have been derived from the erosion of older beds, so that T. parki may be older than Castlecliffian.
It is easily distinguished from T. rossi by the double rib bounding the posterior area, by the narrower rib-interspaces, by the more narrowly rounded umbo yet more inflated disc, and by the considerably smaller anterior lateral tooth, and lack of a deep socket above it.
Specific Names to be Deleted or Suspended.
Hemicardium cordatum Hector.
1886. Outline N.Z. Geol., p. 56, fig. 19, no. 7.
Locality: Maheno, Oamaru (by a misprint written Mahemo).
The specimen that served as a basis for Hector's figure has not been found, and unless it comes to light, the species cannot be identified even at a guess. Consequently H. cordatum must be suspended from our lists. The figure shows a shell having distant beaks bounding a wide area with a ligamental chevron. It thus appears to represent a Cucullaea or a Glycymeris, certainly not a Cardium, which has beaks springing from the dorsal margin. The only Geological Survey collection prior to 1886 localized at Maheno is No. 498, from fine marly beds below the Ototara stone. The specimens are small and thin shelled, quite unlikely to be accompanied by a Cardium or a Cucullaea 4 inches high.
In Park's collection from this place (1918, p. 44) Suter identified two new species of Cardium. Both are distorted casts of Procardia,
Cardium coxi Hector.
1886. Outline Geol. N.Z., p. 57, fig. 19a, no. 5.
What is in all probability the original of Cardium coxi has now been found in the Geological Survey collections. It bears the locality number 487, which is stated (Rep. Geol. Explor. no. 21) to be from Ngapara, North Otago. Part of this collection consists of rusty casts, among them Monalaria, and Hedecardium cf. brunneri, and these probably represent the real Ngapara collection. The other part of collection 487 consists of grey, unoxidised casts, mostly distorted, identical with collection 47, which is from The Castles, Aorere River. This is the locality given by Hector for C. coxi.
The specimen is a double valved Maoricardium that has been much compressed longitudinally. It has about 40 broad ribs with linear interstices and, antero-ventrally, strong blunt tubercles. Most of the fossils from the locality are too poor to give accurate determinations, but the presence of Struthiolaria cf. prior Finlay and a large Hedecardium cf. greyi suggest a Waitakian age. It is impossible to tell from the single specimen whether there are significant differences between it and strangi or oneroaensis. Of course, if it could be definitely identified with any of these it would take precedence; but, until better material turns up, it seems best to relegate coxi to the suspense list.
Cardium spatiosum gracile Hector, M.S.
This subspecies was listed by Suter in his Alphabetical Handlist of N.Z. Tertiary Mollusca, without any indication of its origin, and again in his Alphabetical List of N.Z. Tert. Moll., 1918, but this time indicating it as a manuscript name. The writer has not been able to find Hector's use of the name, but there is a specimen in Geol. Surv. collection 703, so identified in Suter's writing. It is a decorticated Venericardia. In any case there is a prior Cardium gracile Pusch, 1836, and one of Muenster, 1837.
Cardium huttoni Ihering.
1907. Ann. Mus. Nac. Buenos Aires, vol. xiv, p. 291.
This name was proposed by von Ihering for a Waipara shell that Hutton had identified as the Peruvian C. multiradiatum (Sowby.). The shell figured by Suter (1915, pl. 6, fig. 5) as a topotype is a Hedecardium and on this basis huttoni was synonymized with greyi by Powell and Bartrum (1929, p. 408). It is not certain, however, that von Ihering's type specimen is even generically the same as the Canterbury “topotype”. No formal description was given; but a sentence of description and the locality “Miocene of Waipara” can be taken as legalizing the name. The description is: “The first 6–7 anterior radial ribs are furnished with tubercles; the anterior dorsal margin is raised in the middle and crowded against the beak.” Now the anterior ribs of Hedecardium are not tuberculate, but those of Maoricardium are, and Maoricardium also occurs at Waipara. Until direct evidence is obtained from von Ihering's type material in the Museum of Sao Paulo, the exact application of huttoni must remain in doubt.
Figs. 1, 2, 5.—Hedecardium waitakiense (Suter). G.S. 1821, Wharekuri, X 0.8.
Fig. 3.—Hedecardium cantuariense (Laws). G.S. 1985, Ardgowan, X 0.7.
Fig. 4.—Hedecardium greyi (Hutton). Holotype, X 0.8.
Fig. 6.—Hedecardium olssoni n.sp. Holotype, X 0.75.
Figs. 7, 8.—Trachycardium (Ovicardium) rossi n.sp. Holotype, X 0.6.
Fig. 9.—Hedecardium brunneri (Hector). G.S. 29, Brunner, lectotype, X 1.
Fig. 10.—Nemocardium (Pratulum) quinarium n.sp. Detail of sculpture much enlarged.
Fig. 11.—Hedecardium brunneri (Hector). Cast. G.S. 2119, Green Valley, X 1.
Figs. 12, 13.—Nemocardium (Pratulum) pulchellum (Gray). Seven faths., Tryphena Bay, X 2.
Figs. 14, 15.—Hedecardium waitakiense (Suter). G.S. 1821, showing the cemented right cardinals, 14 from above, 15 from obliquely forward.
Fig. 16.—Nemocardium (Pratulum) quinarium n.sp. Holotype, X 3.
Figs. 17, 18.—Nemocardium (Pratulum) modicum n.sp. Holotype, X 3. (Sculpture detail much enlarged.)
Figs. 19, 22, 23.—Trachycardium (Ovicardium) parki n.sp. Holotype, X 0.6.
Fig. 20.—Nemocardium (Pratulum) pulchellum (Gray). Seven faths., Tryphena Bay, X 2.
Fig. 21.—Ethmocardium woodsi n.sp. Holotype, X 2. (Note internal pits filled by matrix.)
Fig. 24.—Varicardium patulum (Hutton). Holotype, X 0.6.
Fig. 25.—Hedecardium olssoni n.sp. Sculpture detail on posterior area of juvenile only, X 9.
Figs. 26, 27.—Varicardium serum (Hutton). Topotype, X 0.6.
Figs. 28, 32, 33.—Varicardium patulum (Hutton). Clifden, zone 7, X 0.7.
Fig. 29.—Maoricardium gudexi (Laws). Holotype, X 1. (After Laws.)
Fig. 30.—Maoricardium spatiosum (Hutton). G.S. 1101. Waipipi Beach, X 0.7.
Fig. 31.—Procardia dolicha (Suter). G.S. 1286, Terakohe, X 0.6.
Species to be Transferred from the Cardiidae.
Genus Procardia Meek.
1871. Proc. Acad. Nat. Sci. Phil., vol. xiv, p. 184.
Genotype (monotype): Isocardia hodgii Meek. Upper Cret. Missouri. Figured, Meek, 1876, U.S.G.S. Territ., vol. ix, pl. 13, figs. 3a, b.
Procardia dolicha (Suter). (Pl. 37, Fig. 31.)
1917. Cardium (Fragum) dolichum Suter, N.Z.G.S. Pal. Bull. 5, p. 76, pl. 9, fig. 4.
1917. Cardium (Fragum) maorinum Suter, N.Z.G.S. Pal. Bull. 5, p. 77, pl. 13, figs. 7, 8.
These shells generally occur as closed individual with very little of the thin, nacreous shell-material adhering to a much distorted cast. No New Zealand specimens yet found show the hinge. An almost undistorted, double-valved specimen from G.S. loc. 1286, mud-stone overlying limestone, Terakohe, is figured below. This shows the characteristic flattened anterior end with its pouting middle zone and large, deeply excavated lunule. The escutcheon is long, rather narrow, slightly concave, and bears no radial ribs. The ligamental nymphs are exposed dorsally and are of moderate length. The radials number about 28, being distally subequal in strength, though some of them have appeared during growth. The ribs are wavy and weakly nodulous, the anterior ones progressively somewhat stronger and further spaced. The anterior, flattened area has two or three radials about the periphery, but the main part has only somewhat irregular concentric ridges.
Meek compared his type species with the Upper Cretaceous Cardium ? decussatum Mantell, which has been well figured by Woods (1909, pl. 41, figs, 7–9, pl. 42, fig. 1) under Pholadomya. The New Zealand shells have much in common with these figures, especially in the flattened anterior area, with its pouting medial ridge and deep lunule. Another shell which appears to be closely related to Procardia is Aporema Dall, 1903, orthotype Pholadomya arata Verill from 71–134 faths. off Massachusetts. This species is figured (as Lyonsia ?) in U.S. Nat. Mus. Bull. No. 37, Pl. 45, Figs. 4, 5, 6, and Pl. 65, Figs, 133, 134. Figure 134 is almost a replica of the specimen from Terakohe. The other figures of arata, however, show that there is no deep lunule bound by medial ridge, which characters seem to be all that separate Aporema from Procardia.
Localities: G.S. 757, Cobden Limestone quarries, Greymouth (type of dolichum) (Duntroonian); Cliffs, Port Hills, Nelson (type of maorinum); G.S. 1286, marl limestone, Terakohe (Awamoan); G.S. 967, Waiarekan Tuff near flourmill, Maheno (=Cardium n.sp. of Suter in Park, 1918, p. 44) (Kaiatan).
1917. Cardium facetum Suter, N.Z.G.S. Pal. Bull. 5, p. 76, pl. 13, fig. 6.
Locality: Tuffs under upper limestone, Whitewater Creek, Trelissick Basin.
Suter's holotype of Cardium facetiim is a fragmentary internal cast of a Venericardia. It bears the imprint of 15 radiais, but the total number was probably about 18 or 20. Until good and undoubted
topotypes are found the species is quite unidentifiable and therefore the name must be suspended.
Although the name is useless, unfortunately it still invalidates Cardium facetum Zhizhehenko proposed, in 1936, for a South Russian Miocene (Chokraksk) fossil in Travaux de l'Inst. Geol. de l'Acad. de Sciences de l'U.R.S. tome v, p. 15.
For the sake of completeness, two species, originally described under Cardium but already allotted their correct place, may be mentioned:—
Glycymeris laticostata (Quoy and Gaimard).
1917. Cardium brachytonum Suter, N.Z. Geol. Surv. Pal. Bull. 5, p. 70, pl. 10, fig. 5.
1923. Glycymeris laticostata, (Q. & G.), Marw. T.N.Z.I., vol. liv, p. 66.
The name brachytonum can be synonymized with Glycymeris laticostata without any doubt. The writer, in 1923, gave the page reference as 17 instead of 76.
Venericardia subintermedia Suter.
1918. Cardium (Glans) kaiparaensis Marshall, Trans. N.Z. Inst., vol. 1, p, 272, pl. 21, figs. 5, 5a.
This is an obvious slip, as is shown on Marshall's list, p. 274, where the correct name is given, Cardita (Glans) kaiparaensis. It is synonymous with Venericardia. subintermedia Suter, 1917.
Dall, W. H., 1900. The Tertiary Fauna of Florida. Trans. Wagner Free Inst., vol. in, pt. 5.
—– 1903. idem, vol. iii, pt. 6.
Finlay, H. J. and Marwick, J., 1937. The Wangaloan and Associated Molluscan Faunas of Knitangata-Green Island Subdivision. N.Z. Geol. Surv. Pal. Bull, no. 15.
Fbizzell, D. L., 1936. Preliminary Reclassification of Veneracean Pelecypods. Bull. Mus. roy. d'Hist. nat. de Belg., tome xii, no. 34.
Keen, A. Mtra, 1937. Nomenclatural Units of the Pelecypod Family Cardiidae. Bull. Mus. roy. d'Hist. Nat. de Belg., tome xiii, no. 7.
Laws, C. R., 1940. Palaeontological Study of Nukumaruan and Waitotaran Rocks near Wanganui. Trans. Roy. Soc. N.Z., vol. lxx, pt. 1, pp. 34–56.
Mabwick, J., 1931. The Tertiary Mollusca of the Gisborne District. N.Z. Geol. Surv. Pal. Bull., no. 13.
Park, J., 1887. On the Geology of the Western Part of Wellington Provincial District and Part of Taranaki. Rep. Geol. Explor., no. 18 (1886–87).
—– 1918. The Geology of the Oamaru District. N.Z. Geol. Surv. Bull., no. 20 (n.s.).
Powell, A. W. B.and Babtrum, J. A., 1929. The Tertiary (Waitematan) Molluscan Fauna of Oneroa, Waikeke Island. Trans. N.Z. Inst., vol lx.
Stephbnson, L. W., 1941. The Larger Invertebrate Fossils of the Navarro Group of Texas. Univ. Texas Publ. 4101.
Stewabt, R., 1930. Gabb's California Cretaceous and Tertiary Type Lamelli- branchs. Acad. Nat. Sc. Phil. Spec. Publ., no. 3.
Suter, H., 1907. Descr. Tert. Shells from N.Z. Proc. Malac. Soc. Lond., vol. vii, pp. 207–210.
—– 1914. Revision of the Tert. Moll. of N.Z., pt. 1. N.Z. Geol. Surv. Pal. Bull. no. 2.
—– 1915. Revision of the Tert. Moll. of N.Z., pt. 2. N.Z. Geol. Surv. Pal Bull., no. 3.
—– 1917. New Tert. Moll. Occurring in N.Z. N.Z. Geol. Surv. Pal. Bull., no. 5.
Thomson, J. A., 1920. The Notocene Geology of the Middle Waipara and Weka Pass District. Trans. N.Z. Inst., vol. lii, pp. 322–415.
Woods, H. 1907. Monograph Cret. Lamell. Engl., vol. ii, pt. 4. Palaeontographical Society, London.
—– 1909. idem., vol. ii, pt. 6.
—– 1917. The Cret. Faunas of the North-east Part of the South Island, N.Z. Geol. Surv, Pal. Bull., no. 4.