FOSSIL REPTILES. 325 



to a saurian. They consisted of a vertebra, one side of the 

 lower jaw, some ribs, and some bones of the shoulder, and 

 pelvis. They preserved no gelatine, and did not become black 

 in the fire. 



The vertebra resembled a caudal of some species of croco- 

 dile, in which both faces are plane or slightly concave. The 

 body alone was preserved. 



The jaw has some characters of crocodiles, and others of 

 lizards. It is more long and slender than that of the common 

 crocodile. The alveoli of the teeth are well separated ; they 

 are ranged on a single line. Twenty-seven were observed in 

 the fragment of which we speak, though it was mutilated at 

 the front. The teeth appeared to have been alternately more 

 bulky and slender, and to have been hollowed internally. 



All this agrees with the crocodile, but the composition of the 

 jaw was different. The coronoid process, which is short and 

 obtuse, appertams to the supplementary bone, which, instead 

 of being small and crescented as in the crocodile, proceeds 

 forward between the dentary and opercular bones, and along 

 the internal edges of the teeth over a length of more than 

 twenty-eight alveoli. The opercular is also carried very for- 

 ward ; and, instead of a simple foramen intercepted between it 

 and the angular, and independent of the grand opening behind 

 the opercular and angular which is observed in the crocodile, 

 there is only a single very long aperture, which predominates 

 from this posterior point of the opercular as far as the articula- 

 tion, and which has the complementary and subangular bone 

 above, and the angular below. At the external face, the sub- 

 angular exhibits a sharp longitudinal ridge. The articulation 

 resembles that of the crocodile, but the post-articular apophysis 

 seems to have been a little shorter in proportion. 



From these two pieces alone, it may be pronounced, without 

 hesitation, that they proceed from an unknown reptile ; very 

 probably from some genus intermediate between the croco- 

 diles and saurians, like those already described. Some other 



