AND REPTILIA OF NORTH AMERICA. 



2(>9 



the external portion of the dentary bone in that region beino^ lost, little can be said 

 about it. Professor Owen's plate indicates a ramus whose depth at the last tooth 

 enters 8| times the total length. In our species this depth enters about 5 times. 



BRACHYDECTE3 NEWBERRYI, Cope. 

 Proceed. Acad. Nat. Sci., Philadelphia, 1868, p. 314. Transac. Amer. Philos. Soc, XIV., 1869, p. 14. 



PELION, Wyman. 



Proceed. Acad. Nat. Sci., Philadelphia, 1868, p. 211. Transac. Amer. Philos. Soc., 1869, p. 9. Baniceps, 

 Wyman, Amer. Jour. Sci. Arts, 1858, p. 158, not of Cuvier (Pediculati). 



Three genera are here indicated as pertaining to a lacertiform type of 8tegoce- 

 2)hcdi. In one of these there are abdominal chevrons and no thoi'acic shields 

 {Sauropleura) ; in another {Tuditanus) no abdominal chevrons, and thoracic shields 

 present. These genera are doubtless well defined, but one or the other of them may 

 possibly, not probably, be identical with Pelion. 1 he only specimen of the only 

 species of the latter exhibits an inferior view of a portion of the skeleton, and the 

 obverse, on which the thoracic and abdominal armor could have been preserved, has 

 not come under my observation. The specimen however, does not exhibit any ribs, 

 although the vertebrae are well preserved ; in the two genera above mentioned, well 

 developed ribs are preserved. 



As observed by Prof. Wyman, the genus presents some points of similarity to 

 the Anura. The prolongation of the angles of the mandible is of this character, as 

 well as the general form of the head. The bones of the forearm may be united as in 

 frogs, and the length and curvature of the femur, are seen among these animals rather 

 than the Salamanders. The form of the femur is different from that of Amj^hihamus 

 grandiceps, which also differs in the unossilied condition of the vcrtebrjc and presence 

 of dermal scales. 



PELION LYELLII, Wijman. 



Loci citati. 



SAUROPLEURA, Cope. 

 Proceed. Acad. Nat. Sci., Phila., 1808, p. 315. Transac. Amer. Philos. Soc, 1869, 15. 



Vertebrae and ribs well developed, no fan-shaped processes of the former. Limbs 

 four, well developed and elongate. Ventral armature of slender rods arranged en 

 chevron, the angle anterior. Probably no thoracic armature. 



This is the most lacertilian of the Carboniferous genera, and might almost be 

 suspected to be a reptile were it not for the ventral armature, w^hich is precisely that 

 of OcstocejjJiahcs and other genera. It appears to lack the thoracic shields* of those 



*When I state, Transac. Amer. Philos. Soc., 1869, 16, that Sauvoplcura lacks the ventral armature of O'esioce- 

 phahiK, thoracic armature, is intended. 

 A. P. S — VOL. XY. 3p. 



