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. Seales smooth. Subcaudals bifid. Posterior maxillary teeth 
longer, grooved. 
OXYBELIS AENEUS. 
Dryints AENEUS Wagler, 1824, Spix. Serp., Brazil, 12, pl. IIT. 
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 concave; 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 1+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 413 inches; tail 183. 
Total length 234 inches; tail 114. 
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 
; 4 I g A 
large, pupil round. Maxillary teeth subequal in a continuous series, or 
: A | 
posterior isolated, equal or larger, smooth or grooved. Internasals small, 
