346 



THE GEOLOGIST. 



A. varians. A. Vibrayeanus. A. WoolgarL 



Lewesiensis. 



PYRENEAN OR SOUTH-WESTERN BASIN. 



A. Carolinus. A. Pailletteanus. A. varians. 



Fleuriansianus, Rhotomagensis. Woolgari. 

 Mantellii, tricarinatus. 



JURA. 



A. MantelUL . A, Rhotomagensis, A, varians. 



ARDENNES AND MEUSE. 



A. Falcatus. A. Renauxianus A, Catillus, 



COTENTIN AND THE ENVIRONS OF VALOGNES. 



A. Verneuilianus. A. Lewesiensis. A. Lafresnayanus. 



This series of species furnishes, for the Proven9al basin, 

 sixteen species, or more than half of what are known ; for the 

 Parisian basin, eight ; for the Gulf of the Loire and Sarthe, 

 thirteen ; for the Pyrenean, or south-western basin, eight ; 

 for the Jura, three ; for the Ardennes, three; and for Co- 

 tentin, three. We find that the Proven 9al basin is, as in the 

 Neocomien group, the most abundant in species, and that 

 the cretaceous Gulf of the Loire and the basin of the Pyre- 

 nees in the group of the chloritic chalk, furnish as many and 

 more species than the Parisian basin. An examination of 

 the forms will doubtless furnish me with some curious facts, 

 drawn from the comparison of the local faunas. 



1st. Out of the sixteen species found in the Provencal 

 basin, five are common to the Parisian basin, seven to the 

 Loire, and three to the south-west. iVfter these distinctions, 

 there remain seven {A. Bravaisianus, Deverianus, Ferandia- 

 nus, Papalis, Prosperianus, Requienianus, and Sartousianus), 

 or about the half, which are as yet peculiar to this basin, 



