58. PHEriroNAx. 19 



Praeocular in contact with or narrowly 

 separated from the frontal ; eight or 

 nine upper labials 5. fasciatus, p. 21. ^ 



II. Scales in 25 rows. 



Dorsal scales very strongly keeled .... 6. eutrojois, p. 22. 

 Scales smooth, except the row next to 



the vertebral, which is feebly keeled . 7. chrysohronchus, p. 22. 



1. Phrynonax sulphureus. 



Natrix sulphurea, Woffl. in Spix, Serp. Bras. p. 26, pi. ix. (1824). 

 Coluber poecilostoma, Wind, Beitr. Nat. Bras. i. p. 250 (1825), and 



Ahbild. (1831) ; Sehleg. Phys. Serp. ii. p. 153, pi. vi. figs. 5 & 6 



(1837). 

 Spilotes poecilostoma, Ikim. 8r Bibr. vii. p. 221 (1854) ; Giinth. Cat. 



p. 100 (1858) ; Jan, Icon. G6n. 48, pi. v. figs. 3 & 4 (1876). 



Rostral broader than deep, visible from above ; internasals as 

 long as or a little shorter than the prsefrontals ; frontal as long as 

 broad or slightly longer, as long as its distance from the rostral or 

 the end of the snoat, shorter than the parietals ; loreal longer than 

 deep ; one praeocular, 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, aU 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 posteriorly. 



Tdtal length 2700 millim. ; tail 720. 



Guianas, Brazil, North-eastern Peru, Ecuador. 



A. Labials without black margins ; tail olive or brown, 

 a. cJ (V. 214; C. 129). Cabaros, Upper Amazon. Mr. E. Bartlett 



6. Hgr. (V. 217 ; C. 139). Moyobamba, N.E. Peru. Mr. A.H.RoflfrC.]. 



c. ? (V. 216 ; C. 134). Guayaquil. Mr. Eraser [0.]. 



d. Tg. (V. 216; 0. 136). S. America. Zoological Society. 



e. Yg. (V. 208 ; 0. 140). S. America. Dr. Pye-Smlth 



B. Sutures between some of the labials black ; tail black. 



/. S (V. 217 ; 0. 144). Demerara Falls. 



g. ij (V. 215; 0. 139). S. America. Zoological Society. 



h. Skull. Brazil. 



c2 



