THE EUROPEAN SEAS. 



169 



genera Mitylus, Chiton, Patella, Trochus, Buccinum, 

 Fusus, and Murex. In each of these zones certain 

 species seem to be represented by their analogues, 

 as Mytilus edulis, Chiton cinereus, Patella vulgata, 

 Trochus lineatus, Buccinum undatum, and Fusus 

 islandicus of our coasts are respectively replaced 

 in the Mediterranean by M. minimus, C. siculus, 

 P. scutellaris, Tr. fragarioides, Murex truncidus, 

 and Fusus corneus. 



From his own dredgings and from an examina- 

 tion of the collection of M. Verany, Mr. Jeffreys 

 records as many as 375 species of Piedmontese 

 Testacea, of which some half dozen are new and 

 discovered by himself ; the rest are known forms, 

 having a wide distribution either within or without 

 the Mediterranean. 



The latitude of the Gulf of Genoa is rather north 

 of that of Vigo Bay and the north of Spain. That 

 we may compare like things with like, Mr. Jeffreys' 

 list may be reduced by about twenty, or to 355 spe- 

 cies. Mr. M 'Andrew's north Spanish Testacea amount 

 to 212, giving a difference of 143 species. For the 

 present we must take these numbers as representing 

 these two local assemblages, and, comparing them 

 together, we find that there are 140 species in com- 

 mon, leaving an excess of 215 for the Gulf of Genoa; 

 but of these, sixty-three species are more northern 

 and British, besides having a range down the south 

 coasts of the Peninsula — these will be considered 

 separately ; but they reduce the Piedmontese list to 



