1854.] 93 



longest toe 6-8ths inch ; of posterior to extremity of longest toe Jf inch ; of tail 

 4 inches; total length. 



Habitat. Lower California. 



Gen. Remarks. The contrast between the large carinated scales upon the 

 back, and the small ones upon the sides resembling granulations, is very striking ; 

 the long and slender tail also is remarkable. In these respects Uro-saurus is 

 allied to Tachydromus, but the plates upon the head are very different. 



SCELOPORUS, Wiegmann.' 



ScELOPORUS MAGISTER, nob. 



Sp. char. Larger than any known species of Sceloporus, and remarkable for 

 its large and strongly carinated scales, which are very much denticulated poste- 

 riorly ; anterior margin of aural apertures strongly denticulated ; upper part of 

 head, body and extremities and tail straw color, without spots or blotches ; a 

 black triangular blotch upon each side of the neck, in front of the shoulder, the 

 base below ; two large bluish green blotches upon the abdomen, one on each side 

 and one upon the neck ; the rest of the under surface light straw color ; tail long, 

 very thick at base, tapering near the point ; twelve femoral pores on each side. 



Dimensions. Length of head, neck and body to vent, 4 6-8ths inches; great- 

 est breadth of head 1 inch; length of head If inch ; of tail l-5th inch ; of anterior 

 extremities l inch ; of anterior foot to extremity of longest toe 1 inch ; of pos- 

 terior extremities 1 6-8ths inch; of foot to extremity of longest toe If inch : 

 total length 9 6-8ths inches. 



Habitat. Near Fort Yuma, at junction of Colorado and Gila, also nearTuson 

 in Sonora, upon a rocky soil. 



Gen. remarks. This species is remarkable for its large size and greatly deve- 

 loped spines. It is a much larger animal than the spinosus of Wiegmann, and 

 wants the quadruple series of dark colored spots that exist in that animal. 

 The posterior margins of the scales are strongly denticulated, which is not the 

 case in spinosus, one of the characters of which is " squamis paucidentatis." 

 From horridus, Wieg. it differs in coloration, arrangement of plates upon the head, 

 and in the number of femoral pores, which in the latter are 4 5. 



Sceloporus bi-seriatus, nob. 



Sp. char. Scales of the back much larger than those upon the sides. Five 

 frontal plates in two rows ; the middle of the anterior row largest ; four inter- 

 nasals ; two very small plates between the anterior row and rostral ; two vertical 

 plates ; one large plate on each side of the occipital, and two in front of them; 

 posterior border of scales not denticulated. A narrow brownish vitta across the 

 head near the middle of the superciliary plates ; coloration of head resembling 

 that of undulatus ; light ash grey above, with a double row of dark-colored spots 

 upon the back on each side of the dorsal line, extending a short distance upon 

 the tail ; extremities ash colored above, banded with black ; under surface 

 silvery grey, with two blue blotches, one on each side of the abdomen, and a 

 blue blotch upon the chin ; 20 femoral pores. 



Dimensions. Length of head, neck and body to vent, 3 inches: of tail 4 

 inches ; length of anterior extremities 5-8ths inch ; of foot anteriorly to extremity 

 of longest toe 5-8ths inch ; of posterior extremity 1 inch ; of foot posteriorly to 

 extremity of longest toe 1 inch ; total length 7 inches. 



Habitat. Borders of El Paso Creek and in Tejon Valley. Constantly climb- 

 ing up trees, when scared, to a distance of twenty or thirty feet, running along 

 the ground and up the trees very quickly. 



Gen. remarks. Wants the undulating lines or bars of undulatus, these being 

 replaced by the spots above described; the scales upon the sides are also 

 much smaller than those of undulatus. This species resembles very closely 

 the variabilis of Wiegmann, and is probably the same, notwithstanding cer- 

 tain differences in the description. In the absence of a good drawing, or authen- 

 ticated specimen, we cannot pronounce, positively, whether they be the same 

 or not, although inclined to the former opinion. Thus the head, according to 



