BIBLIOGRAPHY OF 1878. 351 



In the second section is cited a list, with localities, of 8 Brachio- 

 poda and 561 Mollusca (including 176 Acephala, 2, Pteropods 

 362 Gastropods, and 21 Cephalopods). Of these however, 21 are 

 considered doubtful. For comparison, the numbers inhabiting 

 the British seas are cited, thus; 5 BracJiiopods, 167 Acephala, 2 

 Pteropods, j6j Gastropods and 12 Cephalopods, total 549 species. — 

 The Mediterranean fauna includes 1,015 species {\o Bj^achiopods, 

 27J Acephala, 19 Pteropods, 660 Gastropods and 53 Cephalopods^ 

 Of the 569 species in the French Oceanic list, 336 are also found 

 in the British and Mediterranean seas, 91 others in the British 

 seas but not in the Mediterranean, 82 in the Mediterranean but 

 not in the British seas, while no less than 60 are found neither 

 in the British nor Mediterranean Seas. 



The 4th, 5th, 6th and 7th sections are devoted to detailed com. 

 parisons of these various lists, while the 8th deals with the origin 

 of the marine mollusca of the French Oceanic Coast, from a 

 geological point of view — the conclusion being that the fauna 

 includes more species of Mediterranean than of British origin and 

 that it is consequently of a most pronounced Mediterranean type. 

 But the great fact elicited is the extensive range of most of the 

 species, both now and in the past. Out of 380 fossil forms, 159 

 were common to the Northern and Mediterranean seas, and the 

 same may be said of 336 out of the 559 recent species. 



The 9th section treats of the changes in the limits of the 

 habitat of the species, and the loth of the species which are fossil 

 in England and no longer exist there at the present time, but 

 which now live in the French and Mediterranean seas. The nth 

 treats of the fossil species of the Mediterranean basin which do 

 not now exist in that sea, but are to this day found living in the 

 French and British seas. The 12th treats of the recent extension 

 of species of Mediterranean origin; the 13th of the influence of 

 ocean-currents, the 14th of bathymetrical distribution, the T5th 

 of the species found at extreme depths in the Gulf of Gascony ; 

 while a bibliographical index concludes the paper. 



