72 COLUBRID. 
posteriorly. Head distinct from neck ; eye large or rather large, 
with round pupil. Body elongate, more or less compressed; scales 
smooth or keeled, the laterals smaller and oblique, with apical pits, 
in 10 or 12 rows; ventrals rounded or obtusely angulate laterally. 
Tail long; subcaudals in two rows. 
Centra] and South America. 
Synopsis of the Species. 
I. Scales in 12 rows; anal usually divided. 
Four or more rows of scales keeled .... 1. sewcarinatus, p. 72. 
Scales smooth, or only the two middle 
rows keeldd .......... iets eae ote 2. carinatus, p. 73. 
II. Scales in 10 rows. 
Anal entire; scales smooth, or only the 
two middle rows keeled .......... 3. fuscus, p. 75. 
Anal divided; scales smooth ........ 4. melas, p. 76. 
Anal divided ; scales keeled .......... 5. grandisquamis, p. 76. 
1. Herpetodryas sexcarinatus. 
Natrix sexcarinata, Wagl. in Spix, Serp. Bras. p. 35, pl. xii. (1824), 
and Syst. Amph. p. 180 (1880). 
? Natrix cinnamomea, Wag. l.c. p. 20, pl. vi. fig. 1 
Erpetodryas quadricarinatus, Bore, Isis, 1827, p. 548. 
Herpetodryas carinatus, part., Schleg. Phys. Serp. ii. p. 175, pl. vii. 
figs. 5-7 (1837) ; Dum. § Libr. vir. p. 207 (1854) ; Jan, Icon. Gén. 
31, pl. ii. fig. 1 (1869). 
carinatus, Boettg. Zeitschr. f. ges. Naturw. lviii, 1885, p. 288. 
sexcarinatus, Bouleng. Proc, Zool. Soc, 1891, p. 855. 
Eye smaller than in H. carinatus. Rostral broader than deep, 
just visible from above; internasals as long as or a little shorter 
than the prefrontals ; frontal once and one third to once and two 
thirds as long as broad, as long as or a little longer than its distance 
from the end of the snout, a little shorter than the parietals; loreal 
longer than deep; one pre- and two postoculars ; temporals 142; 
eight or nine upper labials, fourth and fifth or fifth and sixth 
entering the eye; five lower labials in contact with the anterior 
chin-shields, which are a little shorter than the posterior. Scales 
in 12 rows, four or more of which are distinctly keeled. Ventrals 
indistinctly angulate laterally, 142-159; anal divided (rarely 
entire) ; subcaudals 100-128, Uniform brown or olive above and 
on the outer ends of the ventrals; head often reddish; upper lip 
and lower parts yellowish. 
Total length 1350 millim.; tail 450. 
Venezuela, Brazil, Paraguay. 
