FROM TEXAS AND MEXICO. 133 



SCELOPORUS COUCHII Baii'd, 1858. 



Monclova, Mexico. 



Head shields smooth ; a series of broadly dilated trans- 

 verse supraoculars ; two canthal scales ; occipital large, 

 about as broad as long ;. parietals small, three on each side ; 

 two frontoparietals, in contact behind the frontal ; anterior 

 border of the ear with four or five pointed slightly enlarged 

 scales. Dorsal scales as large as ventrals, keeled, blunt- 

 angled or rounded on the posterior margin, longitudinal se- 

 ries gradually converging toward the vertebral ; near eighty 

 series from occipital to base of tail; about twenty scales 

 correspond in length to the shielded part of the head ; lat- 

 eral scales small, very small or granular in the posterior 

 third of the flank, in front of the thigh, keeled, directed 

 obliquely toward the back; ventral scales smooth, blunt 

 or bicuspid ; a series around the middle of the body in- 

 cludes about eighty scales. The adpressed hind limb, with 

 the foot, reaches between the ear and the eye ; tibia as 

 long as the shielded part of the head ; the distance from 

 the base of the fifth toe to the extremity of the fourth is 

 longer than from the end of the snout to the ear. Series 

 of femoral pores thirteen to sixteen each, not meeting. 

 The caudal scales are larger than the dorsals. Male with 

 enlarged post-anal scales. Greenish olive above, with a 

 series of irregular spots of black on each side of the mid- 

 dle of the back, and a lighter band at the upper edge of 

 each flank. Below this light band a black one extends 

 from the eye to the thigh, broken into spots anteriorly, be- 

 coming more distinct and broader as it nears the leg ; be- 

 low the dark band a lighter one runs from arm to leg on 

 the lower edge of the flank. Chin and throat have trans- 

 verse bands of dark and light color, bending backward 

 toward the median line. A black blotch in front of the 

 shoulder. Dark bands across arm and leg. Male with a 

 blue dark-edged blotch on each side of the belly. 



