64 
Transactions of the Boyal Society of South Africa. 
served ; otherwise, the convexity of the valve, its sculpture, its 
rounded margins, and generally sub-cylindrical appearance are 
noticeable details of its structure. It is evidently more closely 
allied to the Liina [Mantellum) gaultina of H. Woods (= Plagio- 
stoma elongata, J. de C. Sowerby and Lima parallela, Orbigny), from 
British and European Albian deposits, than to any other species. 
That form, however, is furnished with depressed valves, and is con- 
sequently wanting in the sub-cylindrical character of the present 
shell. 
In well-preserved examples of L. gaultina the radial costse are 
angulated at the sides and have rather sharp summits, but in the 
cast these details would not be preserved and the ribs would be 
much rounder than they originally might have been. There is 
no indication in the valve described of an intermittent rib between 
the costae such as distinguishes J. Sowerby's Modiola parallela from 
rocks of Lower Cretaceous age, and which even in casts is usually 
preserved. Tate's Lima neglecta {Quart. Journ. Geol. Soc, 1867, 
vol. 23, pi. 7, fig. 4, p. 156), from the Uitenhage formation of South 
Africa is also a closely allied form, being of similar axial propor- 
tions, having much the same costal ornamentation, although 
possessing valves of rather less convexity. 
Again Lima numidica, of Thomas and Peron (Desc. Mollusques 
Cretaces, Explor. Scientif. Tunisie, 1891, pi. 27, fig. 2, p. 217), from 
the Cenomanian of Northern Africa (Tunis) is of somewhat similar 
structure to the foregoing species, although differing in its longer 
posterior side, its relatively greater antero-posterior measurement 
and more numerous costae. It is of interest also to note that 
Stoliczka does not recognise this form of Lima in the Indian 
Cretaceous. 
Locality. — Tributaries of the Manuan Creek. 
Family SPONDYLID^. 
Genus PLICATULA, Lamarck, 1801. 
Syst. Anim. sans Vert., 1801, p. 132. 
Plicatula andersoni, sp. nov. 
Plate II., figs. 15-17. 
Desci'iption. — Shell small, oblique, triangulate, obtusely pointed 
above, depressed, inaequilateral, slightly inaequivalve, height and 
length equal ; anterior margin short, directed obliquely from the 
umbo, afterwards merging into the fan-shaped curvature of the 
