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TOURAINE FAUNA. 



that of the Touraine deposits {Faluns jaunes of 

 Grateloup). 



The Testacea and Echinoderms from these two 

 areas are somewhat peculiar. Extinct or unknown 

 forms are in large proportion ; these will be consi- 

 dered hereafter, but out of rather more than three 

 hundred species of Testacea, there are about eighty 

 which are identical with forms now living in the 

 Atlantic. 



These eighty species are not, however, now asso- 

 ciated on any part of the French Atlantic coast ; 

 their localities are more southern. A better know- 

 ledge than we as yet possess of the Testacea of 

 the West African coast would, in all probability, 

 bring the Falun fauna and that of the present 

 Atlantic into somewhat still closer relationship. 

 For the present, the proportion of recent species 

 may be taken at about 25 per cent. 



Including existing forms, the facies of the whole 

 of the Touraine assemblage is indicative of a more 

 southern province than that which is now found in 

 the parallel of the Loire (or 47° north latitude) : esti- 

 mated according to change in latitude, the diffe- 

 rence may be put at from eight to ten degrees ; or, 

 in other words, at the time of the Falun Testacea, 

 the warm zones of the Atlantic reached by so many 

 degrees farther north than they do now. 



The contrast between the fauna of the Atlantic 

 coast of the department of the Loire and that 

 older assemblage to be seen close by, is far greater 



