CROCODILTANS, LIZARDS, AND SNAKES. 



267 



rows of scales along a broad median si^ace of the back inncli larger 

 tliau more laterally 5 those on the nape as large as those on the top of 

 the head; they are imbricated and angularly tubercnlated, but not 

 carinate. The scales on the sides of body and beneath from chin to 

 anus are excessively minute, almost like shagreen, and arranged in 

 quincunx. The scales, limbs, and upper and lateral surfaces of the tail 

 faintly carinate. Femoral pores filled with a greenish mass. No anal 

 plates. 



Width of head nearly equal to the distance from the nose to ear. 



In the young the general color is olive green, absolutely marbled 

 with dusky (or else dusky, spotted with olive green), with five broad 

 transverse bars between the head and tail. These bars are composed 

 of single red and yellow scales intermixed, and are vscarcely distinguish- 

 able. The tail is black, with three or four broad rings of yellow, dotted 

 with red; much more distinct than the dorsal bars. The under parts 

 are pea green, dotted with black points, the chin and between the fore 

 legs with red. With increasing age these bars disappear to a greater 

 or less degree until the general color above is reddish olive obscurely 

 reticulated with darker; the sides and beneath dotted with black, with 

 an occasional light dot on the back. 



This species differs from those of Grotapliytus in the very heavy, squat 

 form (equal to that of many Phrynosomas), and short limbs and tail. 

 The ventral scales and those along the middle of the back are much 

 larger than those more lateral, and all those beneath are much smaller. 

 The anterior margin of the ear is strongly dentate instead of only 

 crenate. There are no larger post- anal plates. 



From Dipsoscmrus (JorsaJis it is known by the obese proportions, 

 the absence of the single line of keeled scales on the back, and the 

 absence of carination on the upper scales generally. The tail is 

 depressed at the base, not compressed. The belly and gular scales are 

 excessively minute instead of quite large. 



Dr. Stejneger gives the following table of details and measurements: 



Sauromalus aler. 



' Young. 



2 About. 



