Terebratella A. d'Orbigny 1847.
1847. Terebratella d'Orbigny, C. R. Acad. Sci. 25, p. 229.
1927. Terebratella Thomson, N.Z. Board Sci. and Art, Man. No. 7, pp. 292–4.
Type: Terebratula chilensis Broderip 1833, Trans. Zool. Soc. (London), I, p. 141, Pl. 22, fig. 1 = Anomia dorsata Gmelin 1790, Syst. Nat., ed. 13, I, p. 3348. Oligocene to Recent, South America.
Terebratella finlayi n. sp. (Pl. 5, fig. 6).
Shell small, broadly ovate, smooth, featureless. Beak suberect, acute. Beak ridges not prominent. Foramen submesothyrid but nearly mesothyrid, rather large. Valves of about equal convexity. Sides rounded, front squarely truncated. Anterior commissure rectimarginate, with no sign of incipient multicostation. Deltidial plates long and narrow, disjunct. Ornamentation of rather widely spaced growth lines. Punctae small and dense.
Dimensions of holotype: Length, 7mm.; breadth, 5mm.; thickness, 3mm.
Type locality: Tufaceous greensands, Tioriori, Chatham Islands (2 specimens).
Remarks: This species is named after my friend, Dr. H. J. Finlay, who detected the material in the matrix attached to specimens of Notostrea tarda (Hutton) given him by the writer. The species is not likely to be confused with any other member of the genus described from New Zealand.
Terebratella morioria n. sp. (Pl. 4, Fig. 2).
Shell subcircular, beak prominent, acute, hinge-line little curved, sides arched, front rounded. Ventral valve strongly convex, with a pronounced median fold; dorsal valve less convex, with a moderately deep, rapidly tapering sulcus. Anterior commissure sulcate. Beak nearly straight, beak-ridges not strongly carinate, merging into the sides. Foramen very large, submesothyrid, telate. Deltidial plates, small, disjunct. Ornamentation alternate multicostate. Dorsal valve
with 14–15 stout, wide, rounded costae, two of which occupy the floor of the sulcus. Costae of greater width than the interspaces. Ventral valve with three costae on the fold. Increase of costae by bifurcation and interpolation. Punctae small and close. Interior unknown.
Length of holotype, 13mm.; breadth, 12mm.; thickness, 5·5mm.
Type locality: Calcareous tuffs, Momoe-a-Toa, Chatham Islands (a single specimen).
Remarks: The late Dr. Thomson remarked of this form, “Probably new, but resembles the young of T. radiata Hutton.” T. radiata Hutton was described in 18871, from the tuffs and greensands, Broken River, Trelissick Basin, and was figured by Hutton in 19052.
I have not handled specimens of Hutton's species, which is indifferently illustrated. Hutton (1905) gave the following dimensions: Length, 13mm.; width, 12mm.; thickness, 8–10mm.; and recorded about 18 ribs on the ventral valve. It is clear, therefore, that T. radiata is a much more convex shell, and has more costae in shells of the same size. If one may judge from Hutton's figures, the foramen of T. radiata is considerably smaller than that of T. morioria n. sp. The dorsal sulcus, also, would appear to be more deeply excavated in the mainland species. There is no other Tertiary species with which T. morioria might be confused.
Terebratella cf. sanguinea (Leach 1814).
1874. Terebratula sanguinea Leach, Zool. Misc., p. 76, tab. XXXIII.
1887. Terebratella cruenta T. Davidson, Trans. Linn. Soc. London, Ser. 2, Zool., vol. IV, pt. 2, pp. 87–9, pl. XIV, figs. 1–8.
1918. Terebratella sanguinea (Leach) J. A. Thomson, Austral. Ant. Exp., 1911–14, Scient. Repts., Ser. C, vol. IV, pt. 3, p. 31, not figured.
A single, well-preserved individual, from the tufaceous greensands, Whenuataru Peninsula, Pitt Island, appears to belong to this Recent and Wanganuian species. The Chatham specimen is probably not adult, being only 14mm. in length. When compared with Recent specimens of the same size it agrees in shape, but shows a more prominent sulcation which, moreover, is of earlier inception. The costae show no sign of bifurcation. It is possible, therefore, that the Chatham form may prove to be a distinct but closely related species. Further material is needed to settle this point.
Terebratella or Magella n. sp. (?).
The brachiopoda from the Te Whanga bryozoan limestones are very rare. For this reason I notice a single slightly imperfect specimen from this horizon at Whenuataru Peninsula, Pitt Island.
[Footnote] 1. Trans. N.Z. Inst., 19 (May), 1887, p. 406, footnote.
[Footnote] 2. Trans. N.Z. Inst., 37, 1905, pp. 477–8, pl. XLVI, fig. 2.
Fig. 1.—Neothyris thomsoni n. sp. Interior of dorsal valve × 1.3.
Fig. 2.—Neothyris thomsoni n. sp. Holotype, × 1.3.
Fig. 3.—Pachymagas marwicki n. sp. Holotype, × 1.45.
Fig. 4.—Campages toaensis n. sp. Holotype, × 2.5.
Fig. 5.—Campages chathamensis n. sp. Holotype, × 2.6.
Fig. 6.—Terebratella finlayi n. sp. Holotype, × 4.5.
Fig. 7.—Magella pittensis n. sp. Holotype, × 3.
This specimen differs from Terebratella inconspicua (Sow.) and Magella pittensis n. sp. in being more elongate, and having a narrower front. The punctae, too, are apreciably more dense, and the foramen smaller, while the anterior sulcation is less pronounced. It may be that this individual is not adult.
Further material is necessary before this form can be adequately discussed and named.