SAURIA. 51 



latter by the presence of the anterior feet. One species only is 



known. 



Chamsesaura propus, Schn.; Lac. lumbrico'ides, Shaw; Bipede 

 cannele, Lacep. I, xli. Two short feet, four toes to each, with 

 a vestige of a fifth, their internal organization tolerably perfect, 

 connected by scapulae, clavicles and a small sternumj but the 

 head, vertebrae, and in fact the whole remainder of the skeleton 

 resembling that of the Amphisbsense. 



It is from eight to ten inches long, and about the thickness of 

 the little finger j flesh coloured j the back invested by about 

 two hundred and twenty half rings; there are as many on the 

 belly, which meet alternately on the side. It is found in Mexi- 

 co, where it feeds on insects. Its slightly extensible tongue ter- 

 minates in two small horny points; eye very small; tympanum 

 covered by the skin, and invisible externally; two series of pores 

 before the anus. I found but one large lung, and a vestige of a 

 smaller one, as in most Serpents.(l) 



(1) The genera which teraiinate this order of Saurians interpose themselves in 

 so many various ways between the ordinar}' Saurians and the g-enera placed at 

 the head of the Ophidians, that several naturalists now think it improper to sepa- 

 rate the two orders; or tliey estabhsh one, comprizing, on the one hand, the Sau- 

 rians minus the Crocodiles, — and the Ophidians of the Anguis family on the other. 

 But among the fossils of the ancient calcareous formations, we find two much 

 more extraordinary genera, which, to the head and trunk of a Saurian, add feet 

 attached to short limbs, and formed of a multitude of little articulations collected 

 into a species of oar or fin, similar to the fins or fore feet of the Cetacea. 



One of these genera, Icthtosaurus, had a thick head attached to a short neck, 

 enormous eyes, moderate tail, an elongated muzzle armed with conical teeth 

 fastened in a groove. Different species, some of them very large, have been dis- 

 interred in England, France and Germany. 



The other, Plesiosauhus, had a small head attached to a long serpentlike neck, 

 composed of a greater number of cervical vertebrae than is found in any other 

 animal known; its tail was short; some of its remains have also been found on the 

 continent. 



These two genera, for the possession of which we are chiefly indebted to the 

 exertions of M. Home, Conybeare, Buckland, &c. inhabited the sea. They form 

 a very distinct family, but what is known of their osteology approximates them 

 much more closely to the common Saurians than to the Crocodiles, with which 

 Fitzinger has associated them in his family of theLoRiCATA; and so much the more 

 gratuitously, as neither their scales nor their tongue, the two characteristic parts 

 of the Loricata, are known. 



