Nuculanidae.

Nuculana (Pseudoportlandia) tahuia n.sp. (Plate 23; Figs. 1, 2.)

This species is closely related to N. solenelloides (Marshall) from Hampden. It differs in being considerably smaller, and in having a relatively greater height compared with the length. This means that the umbos are narrower and more prominent, and the dorsal margins descend more steeply. The posterior margin is narrow and not so abruptly truncated.

Height, 12 mm.; length, 18.2-mm.; inflation (1 valve), 4.5 mm.

Locality: McCullough's Bridge. Tahuian Stage.

When describing his Sarepta solenelloides, Marshall (1919, p. 233) stated: “It may be that this is the species recorded by Hutton from these beds under the name Malletia funiculata, but his specimens seem to have disappeared, and the name is a nomen nudum.” Since N. solenelloides is one of the commonest species at Hampden, there is little doubt that this is the shell Hutton included in his M. funiculata. The specific name funiculata, however, must be recognised, because Hutton gave a reference to Zittel's figure of a Nelson shell (wrongly identified as the Recent Solenella australis Q. & G. = Neilo). Topotypes from the Cliffs, Nelson, resemble N. awamoana Fin., but are only about half the size. The locality, however, does not provide good specimens, so it will be best, until more material is available, to retain awamoana as at present, and keep funiculata for the Nelson shells and such as closely agree with them.

The following, then, must be added to our Tertiary molluscan fauna:—

Neilo funiculata (Hutton).

1864. Solenella australis Quoy and Gaimard, Zittel, Novara Exped., Geol. Theil, 1 Bd., 2 Abt., p. 47, pl. 13, figs. 2a, b (not of Q. and G.).

Holotype: Natural History Museum, Vienna.

Locality: The Cliffs, Nelson. (? Hutchinsonian Stage.)

Nuculana (Jupiteria) hampdenensis n.sp. (Plate 23; Figs. 4, 6.)

Shell resembling N. leachi Marw. and probably directly ancestral. It differs in having a more concave posterior dorsal margin, so that the flat escutcheon is not seen when viewed side on. The sculpture is slightly finer than that of leachi, but similar concentric grooves due to growth pauses are present.

Height, 3.5 mm.; length, 5 mm.; inflation (1 valve), 1.3 mm.

Locality: Hampden Beach. (Bortonian Stage.)

N. hampdenensis is much closer to N. leachi than to N. parleachi Laws, which is easily distinguished by its higher posterior beak.

Poroleda antiqua n.sp. (Plate 23; Fig. 5.)

Shell rather small, differing from lanceolata in having a more concave and descending posterior dorsal margin, and a slightly more descending anterior dorsal margin, causing the umbo to be more prominent. The ventral margin is not so regularly arcuate, being flattened posteriorly so that the posterior beak is slightly constricted.

Height, 3 mm.; length, 8.5 mm.; inflation (1 valve), 1 mm.

Locality: Hampden Beach. (Bortonian.)

The hinge has not been clearly seen, but it appears to agree with the Recent shell. Iredale separated the Recent shells as perturbata from the Pliocene lanceolata without adequate grounds. The differences of proportion given by Finlay (1926, p. 445) do not seem to the writer established. Some specimens of lanceolata in the Geological Survey collection from Kai Iwi have a length rather more than three times their height. Consequently perturbata sinks into the synonymy of lanceolata.