58. PHRYNONAX. 19 
Preocular in contact with or narrowly 
separated from the frontal; eight or —~ 
nine upper 1.2/0) (LSA eae eae se.» Of(fasciatus, p. 21. 
II. Scales in 25 rows. 
Dorsal scales very strongly keeled .... 6. eutropis, p. 22. 
Scales smooth, except the row next to 
the vertebral, which is feebly keeled . 7. chrysobronchus, p. 22 
1. Phrynonax sulphureus. 
Natrix sulphurea, Wagl. in Spix, Serp. Bras. p. 26, pl. ix. (1824). 
Coluber peecilostoma, Wired, Beitr. Nat. Bras. i. p. 250 (1825), and 
Abbild. (1851) ; Schleg. Phys. Serp. ii. p. 153, pl. vi. figs. 5 & 6 
(1837). 
Spilotes poecilostoma, Dum. §& Bibr. vii. p. 221 (1854) ; Giinth. Cat. 
p- 100 (1858) ; Jan, Icon. Gén. 48, pl. v. figs. 8 & 4 (1876). 
Rostral broader than deep, visible from above; internasals as 
long as or a little shorter than the preefrontals ; frontal as long as 
broad or slightly longer, as long as its distance from the rostral or 
the end of the snout, shorter than the parietals ; loreal longer than 
deep ; one przocular, not reaching the frontal; three postoculars ; 
temporals 1+1; eight upper labials, fourth and fifth entering the 
eye; five lower labials in contact with the anterior chin-shields, 
which are as long as or a little shorter than the posterior. Scales 
in 21 rows, all except the outer row strongly keeled. Ventrals 
distinctly angulate, 208-226; anal entire; subcaudals 126-144. 
Yellowish, olive, or brown above, with or without black spots or 
irregular cross bars ; the keels of the scales black ; belly yellow or 
olive, sometimes turning to black eee 
Total length 2700 millim, ; ; tail 72 
Guianas, Bruit North- castoun pica, Ecuador. 
A. Labials without black margins; tail olive or brown. 
a. db (V. 214; C. 129). Cabaros, Upper Amazon. Mr. E. Bartlett 
[C.]}. 
Her. (V. 217; C. 189). Moyobamba, N.E. Peru. Mr. A. H. Roff(C.]. 
b. 
ce. 9 (V. 216; C. 134). Guayaquil. Mr. Fraser [C. |. 
a. Vg. (V: 216; C. 136). S. America. Zoological Society, 
é. Ye. CV. 208 ; C, 140). S. America, Dr. Pye-Smith 
[P.]. 
B. Sutures between some of the labials black; tail black. 
tT: 6 Wio2lr; ©. 144). Demerara Falls. 
Alp Sv. 215; C. 139). S. America. Zoological Society. 
A. Skull. Brazil. 
