LYGOPHIS ELEGAXS. 163 



quite crowded upon the extremities of the scutellae, so as to assume 

 a maculated appearance. 



Loc. Specimens of this species were obtained in the hilly region 

 behind Valparaiso, Chile. 



LTGOPHIS ELEGAXS, Tsch. 



OBSERV. The genus Lygophis, proposed by Fitzinger, is character- 

 ized in the " Fauna Peruana," where the present species is described 

 and figured. 



SYX. Lyyophis elegnns, TSCH. Faun. Peruan. Herp. 1845, 53, PI. vr. 



DESCR. The head is elongated, very much depressed, flattened 

 above, subovoid in an upper view, and quite distinct from the neck. 

 The snout is narrow and rounded, protruding slightly beyond the lower 

 jaw. The cleft of the mouth is concave beneath the eye. The nos- 

 tril is situated between two plates, and the eye, very large, is sub- 

 elliptical in shape. The occipital plates are large ; the vertex plate is 

 elongated, slightly concave laterally, as broad posteriorly as anteriorly; 

 its posterior acute extremity being admitted between the commissure 

 of the occipitals. The supraoculars are nearly as long and quite as broad 

 as the vertex plate, upon the middle of their length. The postfron- 

 tals are angular, one-third larger than the subquadrangular prefrontals, 

 and extend somewhat to the loral region. The rostral is subpyrami- 

 clal. and very concave beneath. The postnasal is a little larger than 

 the prenasal, the nostril perforating equally both plates. The loral 

 is subtrapezoid, with its narrowest angle directed towards the eye. 

 There is but one anteorbital, inferiorly narrow, widening upwards, 

 and sending a triangular projection to the upper surface of the head, 

 without, however, meeting the vertex plate. We observe two post- 

 orbitals, equal in size. There are six or seven temporal shields ; the 

 anterior elongated; the others scale-like, though larger than the scales 

 themselves. The upper labials are seven in number, the third and 

 fourth entering into the orbit ; the first is the smallest ; they increase 

 in size from the second to the fifth, which is the largest, hence dimi- 

 nishing posteriorly. The symphyseal is small, triangular, entirely 



