Quarterly Joiirnal of Conchology. aryy 



coast, e. g., Fiisus coins, L. occurs in prodigious numbers at 

 Inhambane, whilst at Zanzibar and Mozambique I failed to dis- 

 cover the slightest trace of a specimen. Mitrex brevispiuosa, Larn. 

 is still more numerous and with the last is burnt for lime, but at 

 the other two ports I met with very few specimens. Several 

 Naticas are confined to Inhambane and Natal. 



I have already noticed some of the peculiarities of Port Natal ; 

 of 86 species I collected there, I found 2,2> i'l the tropics, and less 

 than half that number at Algoa Bay, not more than one or two 

 species being common to Naial and Cape Town. Between Algoa 

 Bay and Mossel Bay there is little or no difference. Between 

 these ports and Cape Town there is a very great difference, more 

 however in the species than in the genera. 



Cape Point appears to form a barrier, on each side of which 

 the moUusca differ, as do the Algas (Harvey) and Fishes (Pappe.) 

 This is a subject of very great interest, but it is impossible to 

 enter into it thoroughly in a paper of this length. 



A LIST OF WEST AFRICAN SHELLS, INCLUDING 



THREE NEW PLEUROTOM^ AND ONE NEW 



COLUMBELLA. 



By F. P. Marrat, 



The shells here recorded were collected by Captain Davis, 

 of Liverpool, from Madeira to the Gulf of Guinea. 



