APPENDIX C. — REPTILES. 363 



Both of these rows meet in front of the symphysis of the jaw and 

 behind the angle of the mouth, but leave between them a narrow 

 area covered with very small scales. The inferior surface of the 

 head (fig. 8) is very uniform ; the scales which cover this region 

 are small, some subovate, others subquadrangular. The pyramidal 

 scales of the back constitute several irregular rows. One distinct 

 and crowded row borders the outline of the abdomen. The scales 

 on the belly are smooth, subquadrangular or lozenge-shaped, a 

 little larger on the middle than toward the sides. The femoral 

 pores are quite conspicuous (fig. 10), from fifteen to seventeen on 

 each side. 



The general hue of the specimen before us, preserved in alcohol, 

 is olivaceous-green above, lighter below. Behind the occiput, on 

 each side of the neck, there is an elongated patch of black, behind 

 which a very small patch is seen, and, farther backward three or 

 four others in pairs, triangular or quadrangular, the last of which is 

 placed above and in advance of the hind legs. Four or five pairs of 

 spots, diminishing gradually in size, may be followed along the tail. 

 The dorsal patches are bordered with a line of light yellow. The 

 abdomen appears unicolor, but, on careful examination, numerous 

 brownish dots can be observed. The upper portion of the legs has 

 a few small blackish spots. 



The specimen figured is from the valley of the Great Salt Lake, 

 where it was collected by Captain Stansbury. 



Phrynosoma platyrhinos, Girard. 

 Pl. VII. Fig. 1-5. 



The general form of this species is more elongated than usual, 

 the neck not so much contracted, and the head, consequently, more 

 detached from the rest of the body. The shape of the head is as 

 much a characteristic of this species as its structure. We allude 

 to its circular form when viewed from above (fig. 1), and to the 

 flattening of the nose, as exhibited in the profile (fig. 2). The 

 upper surface exhibits two strong occipital spines, and a row of 

 smaller ones on the temporal region, five on each side. The poly- 

 gonal plates of the cordiform and flat vertex assume a symmetrica] 

 arrangement on both sides, so as to divide the space into two 

 ovoidal areas, the outer row of which is composed of larger plates, 

 while those enclosed are smaller and more irregular. Thus, the 



