SYNOPSES AND DESCRIPTIONS. 21 



OXYBELIS. 

 Wagler, 1830. 



Body much elongate, slender ; tail long. Head long, slender ; snout very 

 long, produced. Rostral inferior. Pupil round. No loreals. Nasal entire. 

 Oculars 1 — 2. Scales smooth. Subcaudals bifid. Posterior maxillary teeth 

 longer, grooved. 



OXYBELIS AENEUS. 

 Dryinus aeneus Wagler, 1824, Spix. Serp., Brazil, 12, pi. III. 

 Oxybelis aeneus Wagler, 1830, Syst. Amph., 183. 



Very slender, slightly compressed; head distinct from the neck, long, 

 narrow, crown convex; snout elongate and narrow, sides concaA r e; tail very 

 long and slender, a little shorter than the body. Eye large, pupil round. 

 Mouth deeply cleft, outline sinuous. Crown-shields nine, anterior elongate, 

 parietals broad. Rostral reaching the top of the snout, but not bent back- 

 ward. Internasals long. Prefrontals long, bent down on the side. Fron- 

 tal narrow, tapering backward. Supraciliaries long, broad posteriorly. 

 Nasal long, narrow, entire. No loreal. One anteocular, as broad as long. 

 Postoculars two, lower small. Labials eight, posterior very long, fourth 

 to the sixth in the orbit. Infralabials eight, fifth and sixth larger. Tem- 

 porals large 14-2. Submentals two pairs, posterior larger. Scales long, 

 pointed, in 17 rows, outer and vertebral broader. Ventrals 183. Anal 

 bifid. Subcaudals 197 pairs. 



Light iridescent greyish or silvery punctulate with brown, sides and 

 belly slightly darker. A narrow line of light color along the middle of 

 the belly, more or less -distinct. Irregularly sprinkled with brown spots 

 on the back and flanks. Anteriorly the belly, throat, chin, and labials are 

 nearly white, above this a dark brown border extends from the nostrils to 

 the sides of the neck. Top of head bronzed and clouded. Specimens 

 described from Obispo, Cent. Amer. Total length 41| inches; tail 18f. 

 Total length 23^ inches; tail 11J. 



NATRICINAE. 



Small to large, slender to stout, generally fusiform, approaching the sub- 

 cylindrical in Hydrops; head distinct, subtriangular, muzzle narrow across 

 the nasals; tail slender to stout, commonly tapering. Eye medium to 

 large, pupil round. Maxillary teeth subequal in a continuous series, or 

 posterior isolated, equal or larger, smooth or grooved. Internasals small, 



