350 



MEMOIRS OF THE CARNEGIE MUSEUM. 



at the Bavarian locality, no trace of them having been found in the corresponding 

 deposits in France. In many cases where the same genera occur in both localities, 

 they are found to be represented by different species, as is perhaps natural to expect 

 from the point of view of geographic distribution. 



Besides the fishes, some fifty species of which were known from Cerin during 

 the life-times of Louis Agassiz and Victor ThioUiere, mention should be made of 



MOLARO DE DON 



M» LACHAT 

 1170 



' CROIX, DC L-W ROCHE 



C/»RR1ERE DE CERIN 



^i ^RRRTIQ uE t'Za AMT*"-'^'^*'^ MOULIN QAPRECNiN 



Fig. 1. Geological Section in the Vicinity of Cerin, France. (After Gervais). 



the occurrence of Rhynchocephalian and Pterosaurian genera in the French deposits, 

 also of a considerable number of insects and Crustacea, apparently identical with 

 those which are found in Bavaria. 



Of somewhat different nature lithologically, but yielding approximately the 

 same ichthyic fauna, and regarded in consequence as the homotaxial equivalent of 

 the beds at Cerin, is the Lower Kimmeridgian bituminous limestone of Orbagnoux, 

 Ain, France. One of the pioneer students of this fauna, Victor ThioUiere of Lyons, 

 writing in 1854, speaks as follows regarding the synchronism of the deposits at 

 Orbagnoux, Cerin, and Solenhofen: 



" Les schistes d'Orbagnoux sont principalement representes dans la collection 

 de M. Itier par leurs vegetaux nombreux et varies; mais ils avaient aussi fourni 

 . . . toute une serie de Thrissops, Leptolepis, Aspidorhynchus, Caturus, Pycnodus 

 [ = Microdon? Eastman] et autres poissons, que j'ai examines avec d'autant plus 

 d'interet qu'ils m'ont donne la pleine conviction de I'identite de la faune ichthyo- 

 logique des schistes bitumineux avec celle des calcaires lithographiques. Cette 

 identite, que je n'avais annoncee en 1850 que sur des preuves moins decisives, ne 

 peut pas plus etre revoquee en doute aujourd'hui, que celles de tout I'ensemble qui 



