THE EUROPEAN SEAS. 



173 



first, Poli and Delle Chiaje; more recently, Can traine 

 and Philippi ; nor must Milne Edwards be forgotten, 

 who, in his Sicilian researches, put on the helmet 

 of the submarine diver, and passed whole hours in 

 collecting and observing beneath the clear waters of 

 that sea. 



For all purposes of numerical and other com- 

 parisons the work of Philippi is the best guide as 

 to the Mollusca of the central Mediterranean ; he 

 there enumerates 522 species of Testacea, and the 

 whole assemblage is presented in its relations to the 

 older fauna of that area, as exhibited in the tertiary 

 strata of Italy and Sicily, as well as with those of 

 certain remote faunas of the present period. 



If Philippi's 522 species are taken as a fair 

 and typical representation of the Mediterranean 

 Testacea, and the species which are both recent 

 and fossil, amounting to 360, be deducted, the re- 

 mainder, 162, gives the difference between the pre- 

 sent fauna and a former one. 



Comparing this typical assemblage with our own, 

 we have 





British. 



Sicilian 



and 

 Italian. 



Difference. 



Common 

 species. 



Bivalves 



156 



188 



32 



83 



Pteropods . 



4 



13 



9 





Gasteropods 



232 



313 



81 



57 



Cephalopods 



14 



15 



1 



7 



Philippi took the works of Fleming and Montague 



