SNAKES. 53 



tip, those of the outer row twice as large as the other ones, entirely 

 rounded, and much imbricate. Anal bifid. Posterior maxillary 

 tooth very long and deeply channeled ; all the other teeth equal 

 in length. — Above and beneath brown ; beneath paler, with two 

 narrow, lateral, uninterrupted black stripes from the chin to the 

 tip of tail; along the middle of belly are two other punctated 

 lines, more or less conspicuous ; from the nostril, through the 

 eye, along the sides of trunk and tail, a narrow black stripe ; each 

 labial behind black-edged ; an erect streak dividing the rostral in 

 two equal parts ; on the neck a medial yellowish line conspicuous. 

 Length of cleft of mouth |-" ; breadth of hinder part of head tV" > 

 length of tail 4^" ; total length 23". 



2. TOMODON DORSATUS. 



Dum. Sf Bibr. vii. p. 934. 



Scales in very oblique rows ; nasal single, long, occupying the 

 place of a loreal shield. Head triangular, broad behind, pointed 

 in front; body rather elongate. Ohve, with two brown longi- 

 tudinal bands along the back of trunk and tail. 



a. Adult. Rio Janeiro. Presented by A. Fry, Esq. 



Description. — Vertical narrow, twice as long as broad, lateral 

 margins nearly parallel ; rostral not reaching the surface of the 

 snout ; one anterior, two posterior oculars ; seven upper labials, 

 the third and fourth touching the eye. Scales in seventeen 

 longitudinal rows, transverse rows very oblique; 135 ventral, 

 65 subcaudal shields. Above olive; crovNTi of head occupied 

 by a large brown blotch, forking behind in two broad, lon- 

 gitudinal, dorsal bands, reaching the end of tail ; between them 

 the vertebral row of scales olive-coloured ; beneath uniform pale 

 olive ; a brown streak from the anterior ocular through the eye 

 to the angle of mouth. Head cordate, very distinct from neck; 

 body and tail elongate. Posterior maxillary tooth very long. 

 Head 6'" broad, 6'" long; trunk 18"; tail 6". 



3. Xenodon, Boie. 



Body stout ; belly flat ; head short, broad, flat ; crown with 

 broad, short shields ; tail stout, tapering ; eye large ; two pairs 

 of frontals ; one loreal ; one or two anterior, two or three pos- 

 terior oculars ; two nasals, nostril between ; rostral moderate, 

 reaching the surface of head. Scales generally much imbricate, 

 and in very oblique rows, smooth in the South American, keeled 

 in the Indian species. Posterior maxillary tooth longest, not 

 grooved. South America ; East Indies. 



