ISO 



THE EXTINCT BATRACHIA, REPTILIA 



process. In this, these animals resemble the Testudinata, but in this only, for it is not 

 attached to the prootic in front as in them. In all the species of the order 1 have seen, it 

 is characterized by the presence of an oval, pit, with mouth making a, strong angle with 

 the surface. It is situated just in front of, sometimes within the margin of, the meatus 

 auditorius externus. Its rise; is uncertain, hut there is some probability that it received 

 the extremity of an osseous or cartilaginous styloid stapes. A groove on the under side 

 of the susponsorium would accommodate such a rod, and in a position nearly similar to 

 that which it occupies in many of the Ophidia. Nevertheless its extremity would have 

 to he a little recurved in order to enter the pit in question. 



In both families of the order there is a, zygomatic or squamosal arch, hut it is very 

 doubtful whether any malar arch exists. There is no connection by malar or quadrato- 

 jugal posteriorly. 



The chevron bones of the caudals, as is well known, are highly developed. They re- 

 semble those of some Saurians. This is an important character, for these; elements do not 

 exist in the Ophidia, where hypapophyses takes their place. A structure somewhat re- 

 sembling the latter, seems to exist in Llasmosaurus. 



The parietal fontanolle is similar to that seen in Laeertilia. and Sauropterygia. 



The six characters in which it resembles the Lacertilia are shared by at least one 

 other order of Reptiles. In its lacertilian characters it approaches nearest the Yaranidae, 

 which themselves offer some approximations to the Ophidia. Tin; elongation of the 

 prootic anterior to the internal ear is a character of all the slender-tongued lizards, and 

 the long superior nostrils and lack of malar arches belong only to the Varan'. 



The singular manner in which the opisthotic is supported is only paralleled, so far as 

 I am aware, by the Ophidian family of the Tortricidae, where it is similarly projected 

 from the grasp of the prootic and cxoccipital, as snsponsor of the quadratum. In Cylin- 

 drophis the parietal and part of the supraoccipital enter the connection also. 



With reference to the limbs, Cuvier says, "that very few hones of the extremities of 

 Mosasaurus have been found, and their rarity was such that, for a, moment, he was led to 

 doubt whether the animal possessed limbs." He states that he was soon undeceived by 

 recognizing a bone of the pelvis which certainly belonged to Mosasaurus. The hone con- 

 sidered to be a pubis, resembling that of the Monitor, as figured in the Ossemens Kossiles. 

 Cuvier further says, that among some fossils from Seichom he detected a. scapula, resem- 

 bling that of the Monitor; and subsequently received drawings from Maastricht of a. cla- 

 vicle resembling that of a, common Lizard, and also a coraeoid bone. From the specimens 

 and figures Cuvier supposes the shoulder of the Mosasaurus to have exhibited a ('lose re- 

 semblance to that of the Lizards. After remarking that he had been unable to procure 

 any long bones of the limbs of Mosasaurus, he expresses his views in regard to certain 



