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).

Venericardia sp.indet.

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