Mollnsca from the Bokkcveld Bcch. 241 



PLEUEOTOMAEIA aff. KAYSERI, Ulrich. 

 (PL XXX., fig. 3.) 



One broken internal cast (No. 70 f.) of a large heliciform gastropod 

 is certainly referable to the genus Pleurotomaria. The shell consists 

 of a broad low heliciform spiral, of few volutions (two only are 

 shown in the specimen) ; the whorls are rounded, but slightly 

 flattened above, and show a narrow median flat revolving band ; the 

 ornamentation appears to consist of somewhat irregular undulating 

 striae, transverse to the whorls. The aperture is not perfect, but 

 seems to be subquadrangular, pointed above, rounded below ; and 

 the umbilicus is open, but small. 



Dimensions. — Breadth of shell across basal whorl 32 mm. ; height 

 of basal whorl 17 mm. ; apical angle about 100°-120°. 



Affinities. — This form seems closely allied to Ulrich's species 

 P. kayseri " from the Devonian of Bolivia. The North American 

 species P. lucina, Hall, ! from the Upper Helderberg and Hamilton 

 Groups is also allied. 



Localitji. — (No. 70 f.) Hottentot's Kloof. 



BELLEROPHON cf. MORGANIANUS, Hartt and Rathbun. 

 (PI. XXX., figs. 4, 4a.) 



There is one specimen of a Bellcrophon (No. 110) in w^hich the 

 shell is small, subglobose and broad ; the outer whorl is broadly 

 rounded dorsally with a very faint median keel ; the margins are 

 angular ; the whorl increases very slowly in height and breadth, but 

 the peristome is abruptly expanded and flattened out on all sides, 

 rising up erect dorsally and descending steeply ventrally ; and a 

 constriction marks it off from the angular lateral edge of the outer 

 whorl. The umbihcus is of moderate size and deep, with sharp 

 angular margins. 



Dimensions. — Height 11*5 mm. ; width of outer whorl behind 

 peristome 9"0 mm. ; height of whorl behind peristome 4-5 mm. ; 

 diameter of umbihcus 3-5 mm. 



Affinities. — The widely expanded mouth resembles B. macrostoma, 

 Roemer, I but the shape of the shell is quite different. In general 



* Ulrich, op. cit., p. 40, t. ii., tij^s. 6«, b, 7. 



t Hall, Palaeont. New York, vol. v., pt. ii., 1879, p. 67, pi. xviii., figs. 1-11. 



I Eoemer, Rhein. Uebergangsgeb., p. 80, t. ii., tig. 6. 



