REPTILES. 219 



are either bluish, reddish, or else of a metallic green, especially on the neck. The upper sur- 

 face and sides of the head are spotted with different shades of black, or dotted with yellow and 

 black. The occipital region and the back, in the male, occasionally exhibit sinuating black 

 lines upon a brownish ground, which itself bears bluish, greenish, or slate-colored spots. Be- 

 neath, the ground-color is whitish, vermiculated, maculated or clouded with greyish lines, 

 spots, or dots. That region sometimes is unicolor in the female. 



This species appears to be quite abundant in the vicinity of Santiago, Chile, whence numer- 

 ous specimens were obtained and preserved. 



Plate XXXVIII, fig. 1, represents a profile view of the female sex of Proctotretus tenuis, 

 size of life. 

 fig. 2^ is an under view, showing the structure of that region, 

 fig. 3, is an upper view of the head, 

 fig. 4, a side view of the head. 

 Figs. 2, 3, and 4, are slightly magnified. 



PEOCTOTEETDS FEMOEATUS, Girard. 



Plate XL, Figs. 5—12. 



Spec. char. Cephalic plates rugose. Auricular aperture moderate, provided with an arched 

 plate upon its supero-anterior margin, and one or two conical scales beneath and upon the 

 same anterior margin. One series of supralabials. Temporal shields well developed, imbri- 

 cated and carinated. Sides of neck with but one inconspicuous fold, and covered with small 

 carinated scales. Dorsal scales large, carinated, posteriorly acute, and diminishing in size 

 towards the sides. Abdominal scutellas smooth and entire. Posterior surface of thighs granu- 

 lar. Tail elongated and slender. Brownish, with two parallel light vitta3 on either side, and 

 two series of black spots. Abdomen whitish, unicolor; inferior surface of head with greyish, 

 irregularly broken lines. 



Syn. Proctotretus femoratus, Grd. Proc. Acad. Nat. Sc. Philad. VII, 1854, 227. 



Desce. This species has the same slender aspect as P. tenuis, the limbs and tail being devel- 

 oped nearly in the same proportions. The body^ mayhap, is a little shorter, and more slender 

 still; The tongiie and teeth present the same general shape and structure. The head is 

 depressed, and quite declive from the frontal region towards the snout. Viewed from above, it 

 is subtriangular, subtruncated anteriorly. The cephalic plates are of moderate development ; 

 exhibiting upon their surface sinuating, subtubercular ridges, which give to that region a 

 rugose appearance. The vertical, a pair of post-occipitals, and two pairs of postfrontals may 

 be distinguished, amid their number, as the largest. Three postinternal surocularies hold the 

 same relations towards their analogues as the former; a concentric chain being observed upon 

 the inner margin of the surface of the upper lid. The perforation of the nostrils takes place 

 through one single plate more towards its posterior or inferior edge than the anterior. The 

 loral region being considerably reduced by the declivity of the frontal region, there are but 

 one or two loral plates. The suborbital chain is composed of three narrow and elongated 

 plates, provided internally with a conspicuous and sharp ridge or crest; the longest occupying 

 the inferior rim of the orbit and the other two its anterior rim ; whilst the posterior rim is 

 formed by the anterior temporal plates. The surciliary ridge is composed of five or six obliquely 

 superposed plates, smallest posteriorly. The surface of the lids is granular; their margins 

 being provided with a series of very small plates. The rostral is transversally elongated and 



