438 REPORT OF NATIONAL MUSEUM, 1898. 



uate tubeicles from below the trout of the orbit, of which the posterior 

 only is distinctly a horn. It is directed posteriorly, having usually the 

 same direction and length of the occipital. One short acute occipital 

 horn on each side; nointeroccipital. Posterior superciliary plate angu- 

 lar, but not promiuent. Infralabials increasing regularly in size to the 

 posterior, which are not very prominent. Gular scales equal. A strong 

 prehumeral fold, in front of which is a fossa, and in front of this a 

 semicircular fold convex backward with a few larger tubercles on its 

 border. Cephalic scales rugose with points and ridges. Supraorbitals 

 partly separated by a single row of scales. Central supraoculars equal 

 supraorbitals. Anterior and posterior superciliaries separated by two 

 scales. 



Dorsal scales of irregular sizes, the median keeled. On each side of 

 the middle line four rows of widely separated transversely oval scales, 

 with a longitudinal keel and apex slightly raised above the general 

 level, and with a few large scales (smaller than those just mentioned) 

 at their bases, which do not form complete annuli. These large scales 

 alternate in their respective rows, though not regularly, and a few flat 

 scales of intermediate size are scattered between them. Scales of 

 superior surfaces of limbs of irregular sizes, keeled, and larger than 

 those of inferior surfaces, which are smooth except on the tibia, where 

 they are keeled. Scales of inferior surfaces of head and body smooth. 



The hind limb appressed to the side reaches to or nearly to the 

 shoulder. The tail is swollen at the base and then contracts abruptly, 

 the remainder being slender and compressed cylindric. Its pholido- 

 sis is irregular, but it has no lateral fringe. Femoral pores forming a 

 continuous series across the belly, and numbering from ten to twelve on 

 each side of the middle line. 



Measnreme^its (Cat. No. 8316). — Total length, 95 mm.; length to vent, 

 55 mm.; length to gular fold, 15 mm.; length of head above to end of 

 occipital horn, 18.5 mm. ; length of head above base of occipital horn, 

 13.5 mm. ; greatest temporal width of head, 21 mm. ; length of fore leg, 

 29 mm.; length of fore foot, 10 mm.; length of hind leg, 35 mm; length 

 of hind foot, 15 mm. 



In life the color of this species is a light yellowish brown, sometimes 

 with a shade of pink. A blackish spot begins on each side of the 

 nape and extends round to a point anterior to the humerus. There is 

 sometimes a sooty shade on each side from the middle to the groin. A 

 small blackish spot behind the vent on the middle line, and frequently 

 a similar spot on each side of the anterior border of the vent. There 

 are no dorsal spots or crossbais, but the tail is indistinctly annulate 

 with blackish. Under surfaces pale yellowish, immaculate, except the 

 gular region, which is generally indistinctly dusky spotted. 



This small species ranges from western Texas to Arizona and Chi- 

 huahua, inclusive. General Pope sent it from the head waters of the 

 Colorado, on the eastern side of the Llano Estacado, and I traced it 



