54 REPTILES. 



Xenodon, Boie, Isis, 1827, p. 541; Schleg. Ess. ii. p. 80; 

 Dum. fy Bibr. vii. p. 753. Arnphiesma, sp., Dum. fy Bibr. vii. 

 p. 737. Tropidonotus, sp., Boie, I. c. p. 535 ; Schleg. Ess. ii. 

 p. 310. Ophis, Wagl. Syst.Amph. 172. Coluber, sp., Cerastes, 

 sp., auct. prior. 



1. Xenodon severus. 



Coluber severus, Linn. Mus. Ad. Fried, t. 8. f. 1 ; Syst. Nat. 

 ed. xii. t. i. p. 379. Cerastes severus, Laur. Syn. p. 84. (Lacep. 

 Quadr. Ovip. et Serp. ii. p. 106, belongs to Clotho arietans) ; 

 Bonnat. Ophiol. Encycl. pi. 13. f. 19. Coluber breviceps, Shaw, 

 Gen. Zool. iii. p. 430. Coluber versicolor, Merr. Tent. p. 95. 

 The Currucuicui, C. saurocephalus, Wied, Biitr. p. 359. pi. 2. f.6. 

 Xenodon saurocephalus and X. ameus, Boie, Isis, 1827, p. 541- 

 556. Ophis severus, Wagl. Syst. Rept. p. 172; Fitz. Syst. Rept. 

 p. 28. Xenodon severus, Schleg. Ess. pi. 3. f. 1-5 ; Dum. fy 

 Bibr. vii. p. 756. 



Scales in very oblique rows ; ventral shields not more than 

 145. Head large, obtuse, body thick, tail short. In younger in- 

 dividuals, back with about twelve large cross bands, and belly with 

 black sjjots, both disappearing with age. 



Adult specimens : — 



A. Uniform brownish grey. 



a. Demerara. From Mr. Snellgrove's Collection. 



b. Very large. Demerara. From Mr. Snellgrove's Collection. 



c. Berbice. Presented by Lady Essex. 



d. Very bad state. Sine patria. From Mr. Mather's Col- 



lection. 



B. Grey ; some scales black, and forming together square black 

 spots. 



e. Very large male. Para. From Mr. Stevens's Collection. 



C. Grey, with eleven large black cross bands. 



/. Head injured. Para. Presented by R. Graham, Esq. 

 g. Berbice. Presented by Lady Essex. 



Half-grown specimens : — 

 A. With whitish cross bands. 



h. Venezuela. From Mr. Dyson's Collection. 



i. Surinam. 



k. Discoloured. Sine patria. From Mr. Bartlett's Collection. 



