PHRYNOSOMA DOUGLASSII. 103 



single row of spines, that give the serrated margin. The thorax and abdomen 

 are covered with smooth rhomboidal scales. 



The tail is broad, thick and flat at its root, but soon becomes small, and 

 terminates in a point; above it is covered with scales and small tubercles, the 

 points of which are shghtty elevated; similar points are scattered along the lateral 

 margin of the tail, but by no means form that beautiful serrated edge seen in the 

 Phrynosoma coronata. 



The abdomen is covered with large, smooth, rhomboidal scales, elongated 

 posteriorly. The vent is transverse, with small scales both before and behind. 



The anterior extremities are large, covered above with rhomboidal carinated 

 scales, and with a row of points along the front of the fore-arm; below, the scales 

 are smooth and small; there are five fingers, distinct, and each furnished with a 

 short, delicate, curved nail. The posterior extremities are but slightly larger, 

 and are covered like the anterior, with the exception of a few spines scattered 

 about the thighs and legs. There are eighteen femoral pores, well developed. 



Colour. The head is brown above, as well as the tubercles; the chin is silver- 

 ^vhite, with a few dusky circular spots. The superior surface of the neck and 

 trunk is light grey, with dusky spots and bands, and with a broad vertebral band 

 of yellowish-white; on each side of this vertebral line at the neck is an oblong 

 dark chestnut blotch, reaching to the shoulders; the throat is silver-white. The 

 trunk is marked with dark blotches, placed transversely, but none of them unite 

 at the vertebral line. The thorax and abdomen are silver-white, with minute 

 dusky spots. The tail is coloured like the back, but is more completely banded 

 towards the tip; the inferior surface is silver-grey. The anterior extremities, as 

 well as the posterior, are grey above and silver-white below. 



Dimensions. Length of head, 8 lines; of body, from head to vent, 2 inches 8 



