NATURAL SCIENCES OP PHILADELPHIA. 63 



Sj). Char. Three horny projections on each side of the muzzle, the anterior 

 small, the posterior which is immediately over the nostril quite long. 



Description. The head is more or less triangular above, covered with scales, 

 very strongly carinated, the carinations so developed as to assume the form of 

 triangular leaf-like projections, giving a sensation of roughness to the latero- 

 superior upper part of the head ; there are three or four scales immediately 

 within the circular row above surrounding the eye, which are larger than the 

 others ; the carinie of these scales are less f )liated than the rest, and re- 

 semble spines ; the eye is of moderate size, ovoid in shape, and somewhat 

 projecting; the nostrils are large, on a line with the eye, three lines from it and 

 ar^not lateral, but look upward and outward; there are three foliated scales 

 upon each side of the muzzle, the posterior 6 lines in length ; the rostral plate 

 is broad and narrow with a convex margin above, concave below, very differ- 

 ent in shape from that of Vipera ammodytes ; there are sixteen supra-labial 

 plates on each side, most of which resemble each other in shape, presenting a 

 serrated margin inferiorly; there are sixteen superior labials which differ from 

 each other, and the anterior are more extended transversely ; the anterior geneials 

 are very large ; the posterior quite narrow ; the pterygo-palatine teeth do not 

 pursue a strictly longitudinal course but diverge posteriorly ; the fangs are 

 enormous and lie entirely concealed in their sheath; the neck is more' narrow 

 than the posterior part of the head, the body quite thick at the middle ; the 

 tail rather shorty terminating in a horn-like pointed projection ; the scales 

 are short and broad, strongly carinated, the inferior row much the largest ; 44 

 may be counted in a row near the middle of the body ; 18 on each side of the 

 neck, 16 rows at the base of the tail. Ah. scuta 128; sub-caud. 31 ; 1 long 

 preanal. 



Coloration. A dark jet black arrowheaded blotch upon the top of the head 

 commencing between the posterior horns, its hinder extremities reaching as 

 far as the posterior margin of the head, the middle portion being lost upon the 

 neck ; this blotch has a narrow border of yellow; upper and lateral part of the 

 head brownish, or brownish mingled with yellow ; a narrow stripe of yellow 

 commencing near the middle of the range of scales which margin the orbit 

 below, and terminating at the inferior margin of the twefth supra-labial, less 

 distinct in older specimens ; posterior to this a large dark-colored triangular 

 blotch reaching from the eye to the angle of the jaw ; a small triangular yellow 

 one upon the side of the head close to its anterior margin, its apex reaching 

 to within a line of the eye; the intervening space between it and the narrow 

 yellow stripe, dark colored, as well as that part of the side of the head in front 

 of the eye reaching to the anterior extremity of the muzzle, on aline with the 

 inferior border of the nostril ; upon the middle line of the back and tail a series of 

 oblong yellow blotches, with triangular emarginations anteriorly and posteriorly, 

 imbedded in a black ground ; sides dark brown, in younger individuals mingled 

 with reddish and yellow, black spotted; the lateral extension of the dark col- 

 ored blotches in which the yellow bars are imbedded triangular in shape; a 

 series of yellow spots on each side at the point of juncture with the abdominal 

 scutes; chin and throat orange mottled with black; abdomen and under part 

 of tail yellow, thickly mottled with black. 



In a very young specimen measuring 10| Inches in length, the coloration of 

 the head is nearly the same, the middle line of the back presenting a longitudinal 

 series of black rhomboids alternating with the lighter colored bars with trian- 

 gular emarginations ; these bars are much shorter upon the anterior part of the 

 body and upon the neck ; the posterior prolongations of the arrowheaded blotch 

 upon the head extend half an inch upon the neck, and present a triangular cut 

 posteriorly ; there is a series of large dark colored spots upon the sides alternating 

 with yellow ; chin and throat dark colored; abdomen thickly maculated with 

 dark subquadrate spots. 



Dimensions. Length 2 inches 3 lines ; breadth 1 inch 11 ; length of body 2 feet 

 8 inches (Fr.;) of tail 6 inches 7 lines. Total length 3 feet 4 inches 10 lines; 

 circumference 6 inches. 



1857.] 



