Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/358

250 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. rounded; lunule rather large, oval; concentric striae very numerous and regular.

This shell approaches A. subtrigona, Munst., but is too oblique for that shell, and possesses much more regular striations.

From the Greenough river, Western Australia.

31. ASTARTE WOLLUMBILLAENSIS, Sp. n. Pl. XII. fig. 12.

Shell small, thick, ovately orbicular, gibbous ; umbones large, mesial ; posterior side rather extended ; anterior slightly oblique ; ventral margin rounded ; shell covered with numerous regular concentric rugae, with deepish interspaces, and with three or four interrupted folds of growth.

Loc. Wollumbilla.

32. Cucullaea inflata, sp. n. Pl. XIV. figs. 1 & 2.

Shell very gibbous and inflated, longer than broad; umbones mesial, much raised, separate, and projecting over a hinge-line which is shorter than the greatest breadth of the valves ; dorsal margin rounded ; posterior and anterior ends much truncated, the former with an obtuse carina, which crosses from the umbo to the dorsal margin, towards which the shell is much angulated ; surface covered by numerous regular concentric striae, which are crossed by faint costae most distinct on the anterior side.

The peculiarly gibbous and truncated form of this shell readily distinguishes it from all the other species of this genus. In its greatest width it does not exceed 2-1/4 inches, whilst, measuring from the umbo to the dorsal margin, it is 3-1/4 inches long, the diameter of the valves being about 2-3/4 inches.

It is from the Greenough district.

33. Cucullaea SEmiSTRIATA, sp. n. Pl. XIV. fig. 3.

Shell transversely oblong; umbones anterior, rather depressed; hinge-area bounded by a lanceolate striated space ; posterior end lengthened, attenuated, and angulated, with an obtuse oblique carina ; anterior end rather short and rounded ; surface covered by very fine concentric striae.

This shell in its general form approaches C. oblonga, with which it is found ; but it has a much finer ornamentation, and the radiating decussating striae appear nearly obsolete, and can only be detected by aid of the lens.

From the Greenough district.

34. Cucullaea, sp.

A third species is found with the above, to be distinguished by its being much narrower or transversely elongated ; but neither of two examples are sufficiently perfect for description. C. oblonga is the most frequent of this genus ; so that four species occur in the Oolite of Western Australia.

35. Cytherea Clarkei, sp. n. Pl. XIII. fig. 1.

Shell large, thick rather compressed, transversely ovate, inequi-