296 Annals of the South African Musexim. 



large, with a small sinus ; ornamented with a few radial ribs crossed 

 by concentric ridges. Posterior ear rather smaller, triangular, with 

 its outer angle obtuse, and with a few radial ribs crossed by growth- 

 ridges. On the left valve the ribs are much narrower than the 

 furrows. 



Length 20 . 19 . 14-5 . 13 mm. 



Height 22 . 21 . 16 . 14 „ 



Affinities. — P. {Chlam7js) amapondensis does not appear to be 

 closely related to any known species. The ornamentation shows 

 some resemblance to that of P. carlottensis , Whiteaves,''' from the 

 Queen Charlotte Islands, but the ribs are less numerous, and the 

 shell is more ovate in outline. 



Remarks. — The type is in the Hamburg Museum. Twelve right 

 valves and two imperfect left valves have been seen. 



Pecten (Chlamys) capensis, sp. nov. 

 Plate XXXV., fig. 10. 



Description. — Left valve ovate, slightly inequilateral, rather higher 

 than long, moderately convex. Antero- and postero-dorsal margins 

 of moderate length ; the remaining margins forming a regular curve. 

 Apical angle about 95°. 



Ornamentation consists of 24 moderately broad, flattened ribs, 

 which are straight or slightly undulating and ornamented with 

 transverse projections at intervals. On some parts of the valve the 

 ribs are of two sizes, alternately larger and smaller — the former 

 starting from the umbo, the latter at some distance from it. Near 

 the anterior and posterior margins the ribs become rather smaller. 

 The interspaces are broad and flattened, and appear to have been, 

 when perfectly preserved, marked with radial striae, which curved 

 outwards on the anterior and posterior parts. 



Ears rather large, attached to almost the whole of the antero- and 

 postero-dorsal margins. Posterior ear rather smaller than the 

 anterior, with its outer angle obtuse. 



Length 20 mm. ; height 24 mm. 



Affinities. — In the general character of its ornamentation this 

 species presents some resemblance to some forms of P. Bohinal- 

 dinus, d'Orbigny, but the height of the shell is relatively less. 

 P. (Chlamys) capensis also resembles P. granulatus, d'Orbigny, f 



* Mesozoic Fossils (Geol. Survey of Canada), vol. i., part 3 (1884), p. 251, 

 pi. xxxiii., fig. 7. 

 t Voyage au Pol Sud, &c. (1847), pi. v., figs. 29, 30, 



