458 



AMBLTCBPHAIIB^. 



16. Leptognathus articulata. 



Dipsas brevis (non B. §■ B.), Cope, Proc. Ac. Philad. 18(30, p. 266. 

 Leptognathus articulata, Cope, Proc. Ac. Philad. 1868, pp. 107 & 

 135. 



Body very slender, strongly compressed. Eye large. Loreal 

 bordering tte eye ; no prseocular ; prsefrontal entering the eye ; two- 

 postoculars ; temporals 2-f3; nine upper labials, fourth, and fifth 

 entering the eye ; first lower labial in contact with its fellow 

 behind the symphysial ; four pairs of chin-shields. Scales in 

 15 rows, vertebrals enlarged. Ventrals 215 ; anal entire ; sub- 

 caudals 135. YeUow, with broad brown entire annuli, which are 

 wider anteriorly than posteriorly, and wider than the interspaces- 

 between them ; top of head, sides, and upper labials in front of 

 the eye, and all the lower labials, brown ; rest of head with 

 numerous short lines on the snout, yellow or white. 



Total length 675 miUim. ; tail 225. 



Costa Eica. 



17. Leptognathus incerta. 



Leptognathus incertus, Jan, Elenco, p. 101 (1863), and Icon. Odn. 

 37, pi. vi. fig. 1 (1870). 



Body slender, strongly compressed. Eye large. Eostral broader 

 than deep, scarcely visible from above ; internasals two thirds the 

 length of the praefrontals ; frontal slightly longer than broad, as 

 long as its distance from the end of the snout, shorter than the 

 parietals ; nasal entire ; loreal slightly deeper than long, bordering 

 the eye; a prseocular above the loreal; two postoculars ; temporals 1, 

 2, or 3+2 or 3 ; nine upper labials, fourth, fifth, and sixth entering 

 the eye ; first lower labial in contact with the symphysial ; three 

 pairs of chin-shields, anterior a little longer than broad. Scales in 

 15 rows, vertebrals moderately enlarged. Ventrals 204; anal 

 entire ; subcaudals 122. Pale brown above, with large dark brown, 

 black-edged cross-bars or alternating spots ; a dark brown spot on 

 each parietal shield ; pale brown beneath, with interrupted darker 

 streaks. 



Total length 720 millim. ; tail 220. 



Guianas, Brazil. 



a. 6 (V. 204 ; 0. 122). S. Jos^ dos Campos, Prov. Mr. A. Thomson 

 S. Paulo, Brazil. [P.]. 



18. Leptognatlms argus. 



Leptognathus argus, Cope, Journ. Ac. Philad. (2) viii. 1876, p. 130. 



Eostral very small, triangular, as deep as broad ; loreal and 

 praefrontal bordering the eye in front ; two postoculars ; temporals 

 14-2 ; seven upper labials, fourth, fifth, and sixth entering the 

 eye ; three pairs of chin-shields, anterior longer than broad and in 

 contact with the symphysial. Scales in 15 rows, vertebrals not 



