REPTILES. 15 



Description. — The general form of this new species is similar to that of Pr. Weigmannii, but less 

 elongate and somewhat more depressed, resembling in general appearance some of the forms 

 of the genus Sceloporus. Head covered with rather small and consequently numerous scales, 

 slightly elevated, and separated from each other by distinct and deep lines. A single series of 

 small scales between the labial scales and the orbit. The exterior margin of the ear is entire 

 and even. Scales of the temple and at the sides of the neck wholly granular, the latter very 

 small. The scales of the back are small, flat, with a very low carina, and not pointed at the 

 posterior extremity. There are about twenty rows of dorsal scales. The posterior surface of 

 the thighs is granulated, excepting a small patch near the tail of imbricated scales, similar to 

 those of the inferior surface, as in Pr. Weigmannii. The tail is of moderate length, and the 

 scales which cover it are short, depressed, and obtuse in comparison with those of several other 

 species. The pre-anal pores, which are peculiar to the male, are about ten in number. 



The general colour is gray, with two light longitudinal lines on each side, and a row of 

 black spots along the inner margin of the dorsal ones. The under surface is nearly white, with 

 black dots under the throat. 



The anterior legs, when stretched backwards against the side, reach about two- thirds 

 towards the thigh ; and the posterior when stretched forwards, extend to the shoulder. 



DIMENSIONS. 



Inches. Lines. 



Length of the head 5 



of the body 1 6 



of the tail 3 4 



Total length .... 5 5 



Length of anterior extremities 8 



of posterior extremities 1 2 



It is at first sight extremely difficult to distinguish this species from younger 

 individuals of Pr. Fitzingerii, from which, however, it differs in the more linear 

 form of the supralahial scales, in the absence of imbricated scales on the lateral 

 fold of the neck, the more entire margin of the ear. In the existence of a patch 

 of larger imbricated scales on the posterior surface of the thighs, it resembles 

 /V. Weigmannii; from which, however, it may be at once distinguished by the 

 single row of supralabial scales, the later species having a double row. 



Proctotretus Weigmannii. 



I 



Plate VIII.— Fig. 1, 2. 

 Capite squamis hevibus turn imbricatis tecto ; auribus rotundis margine anteriore 



