SNAKES. 55 



B. Dusky variety. 

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



Young specimens : abdomen white with a medial broad black 

 band, confluent with which is a series of black square biotches 

 on each side. 



m. South America. 



n . Bahia, From the Haslar Collection. 

 6. Para. From Mr. Stevens's Collection. 

 p. Berbice. 



q, r. ? From Mr. Mather's Collection. 



s. Sine patria. Presented by the College of Surgeons. 



2. Xenodon gigas. 



Dum. 8f Bibr. p. 761. 



Anal entire; scales smooth, in nineteen rows; two anterior 

 and two posterior oculars ; brownish, with large rounded black 

 spots. South America. 



No specimen in the British Museum. 



3. Xenodon colubrinus. 



Scales smooth, in very oblique rows ; one anterior ocular ; 

 anal entire. Head elongate ; snout protruding, angular in front ; 

 nostril very large, between two nasals. Crown of head uniform, 

 without spot or streak. Form and coloration of body as in X. 

 rhabdocephalus. 



a. Adult. Para. Presented by R. Graham, Esq. 



Description of the specimen. — Vertical broad, short, anterior 

 and lateral margins of equal length ; rostral just raised to the 

 surface of the snout, broader than high, obtuse-angled above ; 

 anterior frontals large, rather elongate; posterior frontals square ; 

 occipitals rather short; loreal very large, nearly square; two 

 nasals, between them the very large rounded nostril ; one anterior, 

 two posterior oculars ; eight upper labials, the fourth and fifth 

 touching the eye. Scales in nineteen longitudinal rows, trans- 

 verse rows very oblique; 151 ventral, 45 subcaudal shields. 

 Crown of head uniform dusky brown ; a brown marbled streak 

 from the back edge of eye to the angle of mouth. Coloration of 

 body as in X. rhabdocephalus. There are fourteen lozenge- 

 shaped pale-edged blotches on the trunk, and four on the tail ; 

 belly yellowish, brown marbled. Head rather elongate, flat above ; 

 snout protruding, angular in front ; eye large ; form of body as 

 in X. rhabdocephalus. Length of muzzle from the anterior edge 



