84 COLTJBBID^. 



II. Scales in 15 rows, vertebral row strbngly enlarged. , 



3. lentiferus, p. 86. 



III. Scales in 17 rows, vertebral row not or but very slightly 

 enlarged 



A. Anal divided. 



1. Prontal not twice as long as broad. 



Head twice or twice and a half as wide 



as the neck 4. cjemmistratus, p. 86, 



Neck extremely slender, not more than 



one third the width of the head .... 5. graciUimits, p. 87. 



2. Frontal more than twice as long as broad. 



6. inomatus, p. 88. 



B. Anal entire 7. suhcequalis, p. 88. '^ 



1. Himautodes cenchoa. 



Seba, Thes. ii. pi. xvi. figs. 2 & 3 (1735). 



Coluber cenchoa, Linn. S. N. i. p. 889 (1766); Baud. Bept. vi, 



p. 283(1803). 

 Bungarus cencoalt, Oppel, Ann. Mus. xvi. 1810, p. 392. 

 ~^. Dipsas cenchoa, Wied, Beitr. Nat. Bras. i. p. 396 (1825) : Qunth, 



Cat. p. 174 (1858), and Biol. C.-Am., Bept. p. 175 (1895). 

 weigelii, Fitting. N. Class. Bept. p. 59 (1826) ; ScMeq. Thus. 



Serp. ii. p. 278, pi. xi. figs. 19 & 20 (1887). 

 Imantodes cenchoa. Bum. 8^ Bibr. vii. p. 1065 (1864). 

 Himantodes cenchoa, Cope, Proc. Ac. Philad. 186i, p. 296. and 



Amer. Nat. 1894, p. 613. 



leucomelas, Ccpe, II. cc. 



anisolepis. Cope, Amer. Nat. 1894, p. 613. 



Eostral small, broader than deep, scarcely visible from above ;. 

 internasals much shorter than the prsefrontals ; frontal once and 

 one fourth to once and a half as long as broad, as long as or a little 

 longer than its distance from the end of the snout, shorter than the 

 parietals ; loreal as long as deep or deeper than long, rarely a little 

 longer than deep ; one or two (rarely three) prseoculars, frequently 

 a smaU upper and a large lower; two (rarely three) postoculars ,-. 

 temporals 1 or 2+2 or 3; eight upper labials, fourth and fifth or 

 third, fourth, and fifth entering the eye ; four or five lower labials- 

 in contact with the anterior chin-shields, which are as long as or 

 shorter than the posterior. Scales in 17 rows, vertebrals strongly 

 enlarged, the largest broader than long. Ventrals 220-267 ; anal 

 divided; subcaudals 122-175. Pale brown or greyish above; 

 head with dark brown spots or bands which may be separated by 

 narrow light lines ; body with 26 to 58 dark brown or reddish- 

 brown spots or cross-bands edged with darker and lighter, narrowed 

 on the sides, where they may break up into spots ; lower part» 

 whitish, dotted or powdered with brown, with or without a dark 

 streak along the middle of the belly. 



Total length 1100 millim. ; tail 340. 



Mexico, Central America, Tropical South America. 



