360 APPENDIX C. — REPTILES. 



than the others : the lower jaw is bordered with a double row of 

 plates, the small size of which is the most striking feature in this 

 species. The scales on the belly are subtriangular, posteriorly 

 acute, and slightly keeled in the young individual under considera- 

 tion ; they are smooth in the adult. Femoral pores well developed. 

 Lower surface of the body maculated with irregularly elongated 

 blackish spots. 



II. Phrynosoma cornutum, Gray. — (PI. VIII, fig 1-6.) — Same 

 general profile as preceding. Nostrils situated within the internal 

 margin of the superciliary ridge. Occipital and temporal spines 

 longer and more acute than in the preceding species (fig. 1, 2, 

 and 4). A double row of pyramido-horizontal and abdomino-peri- 

 pheral scales. Scales on the inferior surface of the head small 

 and slightly keeled, of a general uniformity, except one row on 

 each side somewhat larger, pyramidal, acute, slightly raised and 

 directed horizontally outward and backward (fig. 3). A series 

 of very large, inframaxillary plates, sharp on their outer edge, the 

 posterior one of which is transformed into a spine. The plates 

 lining the margin of the jaws are not prominent. The scales of 

 the belly are prop6rtionally small, subquadrangular, posteriorly 

 very acute and keeled. Femoral pores undeveloped or else rudi- 

 mentary (fig. 6). Inferior surface of the body, unicolor. 



III. Phrynosoma coronatum, Blainv. — (PL YIII, fig. 7-12). — 

 Profile declive ; snout protruding ; nostrils situated at the extre- 

 mity of the superciliary ridge (fig. 7). Occipital and temporal 

 spines perhaps less acute, but stouter than in Phr, cornutum (fig. 

 8). A double row of pyramido-horizontal and abdomino-periphe- 

 ral scales. On the lower surface of the head (fig. 9), there exist 

 two double series (four rows) of quite large pyramidal, posteriorly 

 acute, slightly raised scales, inside of which, two double series of 

 much smaller scales are observed, the two innermost rows the 

 smallest. The remaining portion of the lower surface of the head 

 is covered with minute polymorphal scales. The plates of the 

 inframaxillary row are strong, flattened horizontally, and very 

 acute posteriorly : they are very much approximated to the margin 

 itself of the jaw. The scales of the belly are of medium size, 

 smooth, sometimes subtriangular, pointed posteriorly, while others 

 are subquadrangular. Femoral pores very conspicuous, the series 

 of either side coming nearly into contact on the middle line of the 

 belly, forming there a curve, the convexity of which is turned for- 

 ward. Lower surface of body maculated as in Phr. orbiculare. 



