SYNOPSES AND DESCRIPTIONS. 49 



Postoculars two, small. Temporals 24-2, upper anterior small. Labials 

 eight, anterior four small, fourth and fifth under the eye, sixth triangular, 

 seventh and eighth very large, the last separated from the parietals by a 

 pair of large temporals. Infralabials nine, fourth and fifth larger. Sub- 

 mentals two pairs, subequal. Scales large, smooth, in 17 (15 to 17) very 

 oblique rows, outer broad. Ventrals 206, large, broad, bent up on the 

 sides. Anal entire. Subcaudals 72 pairs. 



Brown, lighter posteriorly, with faint indications of zigzag transverse 

 bands of darker. These bands occupy the margins of the scales and are 

 more distinct on the removal of the epiderm. Belly, chin, and throat 

 little lighter than the upper portions. Brazil to Venezuela, possibly to 

 .Mexico. 



Spilotes variabilis. 



DumerilA Bibrm, L854, Erp. Gin. VII, 220. 



Long, slender, compressed; head large, long, subquadrangular in sec- 

 tion across the eye, snout broad, crown slightly convex over frontal and 

 parietals; tail moderately slender, less than one third of the total, taper- 

 ing. Eye large, pupil round. Nostril lateral. Mouth-cleft deep, curved. 

 Teeth equal, smooth. Crown-shields normal, broad. Rostral broader 

 than high, reaching the top of the snout, convex. Prefrontals bent down 

 on the side of the face. Nasal divided. Loreal small. One preocular, 

 large, reaching the top of the head. Postoculars two, equal. Temporals 

 14-2. Labials nine, the anterior three with the fifth and seventh small, 

 eye over the fourth, fifth, and sixth, seventh triangular, allowing the sixth 

 and eighth to meet above it, eighth very large. Infralabials ten, sixth 

 larger. Submentals two pairs, equal. Scales large, much imbricate on 

 the sides, faintly keeled, in 15 rows (irregular, 15 to 17, if small scales 

 irregularly interspersed with the larger are counted). Ventrals 220, 

 broad, bent up on the sides. Anal entire. Subcaudals 121 pairs. 



Anteriorly white (yellow in life), marked with chevron bands of brown 

 or black, posteriorly more dark color. Belly whitish with prolongations 

 from the dorsal bands extending upon it. Head whitish, marked with 

 black (a spot on each parietal and supraorbital margined with black). A 

 large black spot on each side of the neck immediately behind the head. 

 Total length 23| inches; tail b\ inches. Quite variable in colors and 

 squamation. South and Central America to Mexico. 



Mem. — vol. n — 4 



