262 JOURNAL OF CONCHOLOnV, VOL. l6, NO. 8, JANUARY, I922. 



Trochocochlea sagittifera Lam. Gastrnna guinaica Schr. ( = 

 Patella natalensis Krs. abildgaardiana Sp.) 



Ostrea lacerata Hanley. ^Macotna cumafta Costa. 



Ostrea cucullata Born. 



Ten of the above (*) may be expunged as erroneously ascribed to 

 S. Africa, and very probably Clavatula lineaia, O. dolabrahis and 

 D. oiveni should go with them. A. decHvis as S. African rests upon 

 a single example from Durban which differed from the type and 

 sounds, therefore, a doubtful record. 



We have, however, among the rest a residuum of characteristic 

 Cape forms, e.g., P. aperia^ Nassa pcecilosttcta. Patella natalensis, 

 K. mactroides and the Gasfra?ia, whose range extends to Mossamedes 

 or even further North, no doubt by the agency of the Benguela 

 Current. 



Most of the others I regard as W. African littoral species which 

 have worked their way southwards along the coast, e.g., Mactra 

 glabrata, D. rngosus and Tapes corrugates (I see no reason to lump 

 this with T. pullastra). Possibly the Gastrana belongs rather to this 

 category. 



But, though a few Cape skirmishers reach Mossamedes, its moUus- 

 can fauna is eminently W. African : it produces such genera as 

 Pusionella, Pseudolwa, Aspa, Eglisia and Tugonia, and must be 

 almost the southern continental limit of Thais haemastoma L., Area 

 senilis L., Strigilla splendida Ant., Tivela tripla L. and Terebra 

 senegalensis Lam., all of which the late Mr. Shackleford and I received 

 direct from Mossamedes some eight years ago. Further collecting is 

 especially desirable on the northern limits of S.W Africa. In all 

 probability the boundary line of the Cape fauna will prove to be, as I 

 have already suggested, somewhere about the mouth of the Cunene 

 River, which separates British from Portuguese territory. 



In concluding, I should like to express my thanks to Mr. R. Winck- 

 worth for much enlightenment concerning the ocean currents in the 

 Atlantic and for the map which is reproduced on p. 256. 



Paludestrina jenkinsi (Smith) in Somerset N. — While staying at Clevedon 

 in October, 1920, I found this mollusc swarming in countless numbers in a small 

 stream which empties itself near the Pill and is for some distance tidal. Swanton 

 in his Mollusca of Somerset says of P. ventrosa : " In marvellous abundance in a 

 ditch near the Pill, Clevedon (Norman)." Of this species (living) to-day there 

 appears to be no trace in the district, although Mr. Kennard informs me that he has 

 ome specimens labelled " Clevedon " collected many years ago by Canon Norman. 

 It looks as if jenkinsi has ousted its relative from the district. It would be 

 interesting to know if this is happening in other districts. — Douglas Bacchus 

 {Read before the Society, March and, 1921). 



