392 Annals of the South African Museuvi. 



Of the foregoing species nearly all are represented in the collection 

 now examined ; P. antiqua, comes from the Zwartberg Pass ; 

 specimens apparently attributable to P. arcuata, but in a poor 

 state of preservation, come from the same locality and from 

 Gydo Pass. 



P. rudis is represented by typical examples from Uitkomst 

 and an unknown locality and doubtfully from Ezelfontein, while 

 a variety characterised by its more elongated shape comes from 

 Ezelfontein. This variety is represented only by poorly preserved 

 specimens which do not allow of a detailed diagnosis, but in the 

 position of the beaks, sulcus on surface, convexity and marginal out- 

 line, it agrees with the type, only differing in its more elongated 

 shape, one specimen measuring 37 mm. long by 21 mm. high, and 

 another 45 mm. long by 26 mm. high. There is one specimen from 

 Uitkomst of a broken right valve with the dorsal margin and beak 

 imperfect, which may probably be regarded as a short variety 

 of P. rudis ; it is elliptical-subquadrate in shape, as shown by 

 the growth-lines, which are strong and widely spaced ; the posterior 

 margin has the outline of the type ; it measures approximately 

 35 mm. in length and 28 mm. in height. 



Two imperfect internal casts which show the hinge-line and teeth, 

 from the Zwartberg Pass, probably belong to P. subantiqua ; and 

 a crushed specimen from an unknown locality may be compared 

 with P. cf . fecunda as previously described by the author. 



Genus NUCULANA Link., 1807 (= LEDA Schumacher, 1817). 

 NUCULANA INOENATA (Sharpe). 



Two good examples of this shell occur in the collection from 

 Uitkomst and Gydo Pass ; the specimen from the former locality 

 measures 29 mm. in length by 15 mm. in height; and the other 

 (which is rather elongated by crushing and posteriorly is broken 

 off) about 38 mm. in length by 19 mm. in height. 



There is nothing to add to the description already published, 

 except that it appears closely related to N. securiformis (Goldfuss) 

 as illustrated by Beushausen,* which occurs in the Upper and 

 Lower Coblenzian of Europe. Its resemblance to Leda diversa 

 Hall, of North and South America, has previously been remarked.! 



* Beushausen, op. cit., p. 5'J, t. iv., figs. 26-28. 

 f Reed, Ann. S. Afr. Mus., vol. iv., pt. vi., p. 255. 



