xvi MARINE EEPTILES OF THE OXEOED CLAY. 



one (T. gaudryi), from about the horizon of the Fuller's Earth (L. Bathonian) in 

 Northern France. In this Crocodile the prefrontals form slight projections over the 

 orbits, apparently the commencement of the large overhanging prominences seen in 

 Hetriorhynclws. The snout is pointed and the surface sculpture, particularly of the 

 frontal, is not unlike that of some species of Metriorhynclius. Deslongchamps regards 

 this genus as transitional between the Steneosaurs and Metriorhynchs; but the 

 structure of the base of the skull and palate is not well known, so that it is uncertain 

 whether or not there was a large vomer (parasphenoid) as in the latter group. In 

 fact, the presence of this structure in the Geosaurida? suggests that they have probably 

 been derived from a stock widely different from that of the Steneosaurs, in which, so 

 far as is known, it is absent ; and if Teleidosaurus should be found to possess this 

 character, it is the earliest-known member of the family of Avhich the origin and 

 relationships to the other Crocodiles are quite uncertain. 



CHARLES W. ANDREWS. 



Department of Geology, 

 December 1912. 



