68 AMERICAN PERMIAN VERTEBRATES 



Family Pariotichidae 

 Cope, Proc. Amer. Phil. Soc, 631, 1883. 



Reptiles of small to moderate size, with a large, pointed head, 

 short legs and tail. Skull roughened, narrowed in front of the 

 orbits; either tabulare or supratemporal absent, sometimes both; 

 a dermoccipital always present; occipital condyle rounded. Teeth 

 implanted in two or more rows on maxillae, one or more on mandi- 

 bles. Presacral vertebrae twenty-three or twenty-four in number, 

 the arches low, but not transversely expanded, the spines low and 

 small; two sacral vertebrae. Dorsal ribs with expanded proximal 

 end, their articulation continuous from the intercentral space to 

 diapophysis; weak or absent in lumbar region; the anterior dorsal 

 ribs distally expanded (in all?). Slender ventral ribs are present. 

 No cleithrum in pectoral girdle. Limb bones with well-developed 

 articular surfaces; digital fossa of femur not elongate; the adductor 

 ridge not prominent; tibiale and fibulare large; front feet pente- 

 dactylate; phalangeal formula apparently reduced. 



The above definition is based exclusively on Captorhinus and 

 Labidosaurus; I have never studied closely either Isodectes or 

 Pariotichus. The former genus I believe will be found quite 

 distinct; if the latter is also, it must retain the family name Parioti- 

 chidae and another be chosen for Captorhinus and Labidosaurus. 

 All the species which Cope referred to Pariotichus, save the typical 

 one, are now known to be much more closely related to the geno- 

 type of Captorhinus (C. angusticeps) and must be referred to that 

 genus. 



CAPTORHINUS 

 Cope, Proc. Amer. Phil. Soc, XXXIV, 443, 1896. 



? Captorhinus, sp. Plate XXX, Figs. 6, 7. 



A single femur found in the Craddock bone-bed shows such 

 decisive pariotichid characters that there can be no doubt of its 

 relationships. In size it is intermediate between that of the smaller 

 forms of Labidosaurus and the larger forms of Captorhinus, but. of 



