from Southern Nigeria. 107 



inequilateral; costal fine, numerous (about 3G), separated by 

 narrow grooves, convex, smooth. 



Dimensions (largest example), — Length =■ 20, height = 

 20 mm. 



Remarks. — There are several examples of this form of 

 Cardium, whicli appears to be one of the prevailing shells of 

 these deposits. The costte are considerably worn, especially 

 near the ventral margin, but they are quite as numerous and 

 fine as in young e\^m.\AQ,s o? decor ticat am from the English 

 Crag contained in the Searles Wood Collection at the British 

 Museum. Like them, also, the costse become eroded and are 

 frequently divided by a fine central groove, 'ilie s| ecimens 

 may represent the young forms of this species, in which the 

 ribs are continuous over the surface of the valve, whereas 

 adult examples recorded from England are without costal on 

 the posterior side. 



They may be said also to show some resemblance to young- 

 examples of Cardium mxiricotvm, an Atlantic species (West 

 Indies) of Linnaius (Syst. Natui-ai, 1758, ed. x. p. 679), as 

 determined in the Zoological Depa.tment of the British 

 Museum, especially in the number and general formation of 

 tiie costte. 



(?) Gastrana sp. (PI. VL figs. 8, 9) and associated 

 Fish-scale (Pi. VL fig. \<c,). 



Description. — The collection contains a fragmentary right 

 valve of what is doubtfully referred to the genus GastraH( . 

 It is of oval-oblong shape and covered with prominent, equi- 

 distant, concentric laminations of sligiitly infuiidibuliforni 

 character, separated by well impressed sulcations; no radial 

 ornamentation is visible. 



The umbonal region is moderately elevated, oblique, and 

 anterior; the margins of the front and ventral areas are 

 rounded, the postero-dorsal border is straight and oblique, 

 whilst the posterior surface is more or less truncated. 



Dimensions. — Height = 18, length = 22 mm. 



Remarks. — It is in the regular character of the costa?, the 

 truncated posterior side, and the elevated umbonal region, 

 which suggests at first glance a relationship to Gastrana, 

 although the concentric sculpture of that genus shows no in- 

 fundibuliforra character as in the present S[)ecimen. Without 

 more complete material it is difiicult to place such a fragment 

 in its true generic position, and so for present purposes it 

 has been compared with examples of Gastrana laminosa, 

 J. de C. Sowerby, from the British Pliocene beds, a form 

 closely allied to the recent frajil is of Linnaeus. 



