I. The laticostata Group.
Glycymeris laticostata (Quoy and Gaimard). (Plate 1, fig. 1.)
For synonymy and description see Suter's Manual, 1913, p. 851.
A noteworthy feature that has not been remarked upon previously is the difference of the ribbing between the anterior and posterior halves of the shell. The ribs on the latter are narrower and more rounded, and the interstices are wider than those of the former.
Fig. 1.—Glycymer is laticostata (Q. & G.), right valve
Figs. 2, 3.—Glycymeris sp. A. (Uruti)
Figs. 4, 9—Glycymeris lornensis n. sp. Holotype.
Figs. 5, 6.—Glycymeris sp. B (Pakaurangi.)
Fig. 7.—Glycymeris chambersi Marshall. Holotype.
Fig. 8.—Glycymeris traversi (Hutton). Lecotype.
Fig. 1.—Glycymeris callaghani n. sp. Holotype.
Fig. 2.—Glycymeris waitakiensis n. sp. Holotype.
Fig. 3.—Glycymeris shrimptoni n. sp. Holotype
Fig. 4.—Glycymeris treltssickensis n. sp. Holotype.
Fig. 5.—Glycymeris waipipiensis n. sp. Holotype.
Fig. 6.—Glycymeris modesta (Angas). Left valve.
Fig. 1.—Glycymeris callagham n. sp Holotype
Fig 2.—Glycymeris wailakiensis n. sp. Holotype
Fig. 3—Glycymei is sh [ unclear: ] mptoni n. sp Holotype
Fig. 4.—Glycymeris [ unclear: ] trelissickensin n. sp Holotype.
Fig. 5.—Glycymeris waipipiensis n. sp. Holotype
Fig. 6.—Glycymeris modesta (Angas) Left valve
206—Shakespeare Cliff, Wanganui.
Castlecliff, Wanganui (Marshall).
Waihi, near Hawera (Marshall and Murdoch).
749 (in part) — Mouth of Ruarnahanga River, Palliser Bay.
81—Castle Point. (Shell slightly more globose, ribs more regular.)
231—McLean's, Ngaruroro, River, Hawke's Bay. (An old, heavy shell, with beak and ribs like the Castle Point shells.)
Tokomaru (Marshall). (A very worn specimen, but similar to those from Castle Point.)
? 649—Paparoa Rapids, Wanganui River. (One imperfect specimen.)
? 786—Mount Donald, Weka Pass. (An imperfect specimen, more inflated than usual: Pal. Bull. No. 8, p. 42, last list.) This specimen resembles that from loc. 231.
? 246—Cape Rodney, Auckland. (A distorted specimen.)
The locality-numbers are those of the New Zealand Geological Survey (see N.Z. Geol. Surv. Pal. Bull. No. 1).
It will be noted that positive identification could not be made in the last three localities. The shells are undoubtedly of this group, but may represent different species.
McCoy (1875, p. 26, pi. xix, figs. 9–13) has described and figured specimens attributed to this species from the “Lower Tertiary ” of Bird Rock, Geelong; Mount Eliza and Mount Martha, at Schnapper Point. With reference to this, Tate (1885, p. 137) says, “The identification of the fossil and the living species has been disputed by Mr. R. M. Johnston. The material at my command is not sufficient to permit me to express an opinion, though I have little hesitation in accepting Professor McCoy's determination in respect to the fossil represented by fig. 10.”,
Unfortunately, no material from Australia was available for this paper, and opinions based upon figures and descriptions are not so reliable as those based on the actual specimens. However, the excellent figures of the Prodromus show no difference between the anterior and posterior ribbing, so the specific identity of the two shells is open to doubt.
Records to be eliminated from N.Z. Geol. Surv. Pal. Bull. No. 8:—
Page 25. Manaia Beach. These shells belong to the huttoni group, and are here placed as a new species = G. manaiaensis.
Page 30. Lower Awatere, loc. 126 = G. manaiaensis.
Page 31. Starborough Creek = G. manaiaensis.
Page 40. Moonlight Creek = G. manaiaensis.
Page 44. Motunau beds, Weka Pass = G. manaiaensis.
Page 45. Motunau beds, Weka Pass = G. manaiaensis.
Page 45. Motunau beds, Weka Pass = G. manaiaensis.
Page 45. Motunau beds, Lower Waipara = G. manaiaensis.
Page 46. Motunau beds, Mid-Waipara = G. manaiaensis.
Page 53. Kakahu = G. subglobosa (distorted).
Page 57. Pareora, loc. 458 = G. huttoni (worn).
Page 59. White Rock River, loc. 165 = G. huttoni (worn).
Page 85. Bed K, tuffs south of Cape Wanbrow = Venericardia sp. (common in this locality).
In the cases cited above, as well as in the rest of this paper, the specimens have actually been handled. In the case of many other occurrences noted by Suter the specimens are missing from the Geological Survey collections; in fact, no undoubted specimen of G. laticostata has been seen from strata older than Wanganwan.
Cardium brachytonum Suter.
N.Z. Geol. Surv. Pal. Bull. No. 5, p. 17; pi. x, fig. 5, 1917.
The holotype on examination proves to be the cast of a Glycymeris, probably laticostata. In the plate reproduced in Bulletin No. 5 the extremities of the hinge-area have been blocked out by a black background.
Glycymeris traversi (Hutton). (Plate M, fig. 8.)
1873. Pectunculus traversi Hutton, Cat. Tert. Moll., p. 28.
1914. Glycymeris traversi (Hutton): Suter, N.Z. Geol. Surv. Pal. Bull. No. 2, p. 35, pl. iv, figs. 2a, 2b.
In his description Suter gives the locality of the lectotype as Chatham Islands. The actual specimen in the Dominion Museum is labelled “ Loe.? ” However, the shell is almost certainly from Chatham, so Suter's statement may stand.
Buchanan's drawing of this shell, reproduced by Suter (see above), does not represent accurately the wide interstices between the ribs. From the drawing one would take the shell to be inseparable from G. laticostata; this, however, is not so. The interstices are equal in width to the ribs, even at the margin of a 2J in. shell; thus the ribs in G. traversi are noticeably narrower than in G. laticostata. As to Suter's statement that the former is less inflated than the latter, the present examination does not bear out the observation. The inflation is practically the same in shells of equal size. There is very little difference in width between the anterior and posterior ribs.
The shell from loc. 786, Mount Donald, in this paper provisionally placed under G. laticostata, may be the same as the one from Weka Pass placed under G. traversi by Hutton (1873, p. 28). If so, Hutton's record of this species from that locality must be deleted, as the specimen in question has broadly rounded ribs, and so is nearer G. laticostata. No specimen of G. traversi from New Zealand rocks has been seen during this examination, nor can I find a record of its having been identified by Suter.
Glycymeris lornensis n. sp. (Plate 1, figs. 4, 9.)
Shell, medium-sized, suborbicular. to longitudinally oval, equilateral: beaks only moderately raised above the- dorsal margin, which is short, anterior end convex, the dorsal margin sloping; posterior end similar; sculpture consisting of 25 to 30 rounded, radiating ribs which reach the margin but become obscured in some specimens by strong growth-lines, the interstices rounded and narrower than the ribs; margins weakly crenate; hinge-plate deeply encroached on by the ligamental area, even in small individuals, leaving three or four teeth on each side; ligamental area relatively large, steeply inclined, and very closely grooved by about 12 well-incised lines.
Holotype in collection of N.Z. Geological Survey.
Height, 40 mm.; length, 40 mm.; thickness, 14 mm. (one valve).
Material.—Six specimens, none of which is perfect.
Locality.—Conglomerate band in Waiarekan tuffs about 50 ft. below the diatomaceous ooze, 400 yards west of Lorne Railway-station, North Otago. (J. Marwick.)
The actual specimens are from an outcrop above the road near the base of the hill, apparently a slip from, above.
This shell has a more prominent beak than G. laticostata; it is also much smaller; so that young individuals of the latter may be distinguished by their little-developed ligamental area. In most specimens there is an inclination towards a subtriangular shape, and very little difference of width between the posterior and anterior ribs.
Glycymeris chambersi Marshall. (Plate 1, fig. 7.)
1909. Glycimeris chambersi Marshall, Subantarctic Islands of N.Z., vol. 2, p. 701.
1915. Glycymeris laticostata (Q. & G.): Suter, N.Z. Geol. Surv. Pal. Bull. No. 2, p. 49.
Suter thought that this shell was the ovate form of G. laticostata, but several features are displayed which seem to warrant the preservation of Marshall's specific name. The most important is that the area is more densely striated than that of G. laticostata, there being 13 striae in an area 7 mm. wide, while an equal area of G. laticostata has only about 7. In addition, the rib-interstices on the middle of the disc are deeper, and the shoulders are inclined to be narrower and more rounded.
The type-material consists of a pair of valves (one of which is incomplete), enclosing a larger right valve; the heights are 56 mm. and 62 mm. respectively. From the great encroachment of the area on the teeth, the latter appears to be a fully-grown shell.
This species seems to be intermediate between G. lornensis G. laticostata; it is nearer to these than to G. traversi.
Holotype in School of Mines collection, Otago University.