56 MAlSrUAL OF THE MOLLUSCA. 



originally belonged. And when species occur both recent and 

 fossil it is easy to perceive the direction in -which their migra- 

 tions have taken place. 



The Fauna of the Mediterranean has been critically examined 

 by Prof. Porbes and M. Phiiippi, with this result, — that a large 

 proportion of its population has migrated into it from the At 

 lantic, and a smaller number from the Eed Sea, and that the 

 supposed peculiar species are diminishing so rapidly with every 

 new research in the Atlantic, that it can no longer rank as a 

 province distinct from the Lusitanian. 



When the Faunas of the other regions have been tested in 

 the same manner, and disentangled, the result will probably be 

 the establishment of a much greater number of provinces than 

 we have ventured at present to indicate on the map. 



It may be desirable to notice here the extraordinary range 

 attributed to some of the marine species. These statements 

 must be received with great hesitation; for when suflB.ciently 

 investigated, it has usually proved that some of the localities 

 were false, or that more than one species was included. The 

 following are given by Dr. Ejrauss in his excellent monograph 

 of the South African MoUusca : — 



BaneUa granifera : Eed Sea, Natal, India, China, Philippines, 

 New Zealand. 



Triton olearius : Brazil, Mediterranean, Natal, Pacific. 

 Purpura lapillus : Greenland, (Senegal, Cape). 

 Venus verrucosa : (W. Indies), Brit. Senegal, Canaries, 

 Mediterranean, Red Sea, Cape (Australia). 



Octopus vulgaris : Antilles, Brazil, Europe, Natal, Mauritius, 

 India. 



Argonauta argo : (Antilles), Medit., Eed Sea, Cape. 

 Lucina divaricata is said to be " found on the shores of Europe, 

 India, Africa, America, and Australia." {Gray.) In this case 

 several species are confounded. The rock-boring Baxicava has 

 been carried to all parts of the world in hallast, and it remains 

 yet to be ascertained whether the same species occurs in a living 

 state beyond the Arctic Seas and North Atlantic. 



Lastly, the money cowry is always catalogued as a shell of the 

 Mediterranean and Cape, although its home is in the Pacific, 

 and it has no other origin in the Atlantic than the occasional 

 wreck of one of the ships in which such vast quantities of the 

 little shell are annually brought to this country to be exported 

 again to Africa. 



