SNAKES. 179 



blunt muzzle ; eye moderate, pupil elliptical. Rostral rather 

 broader than high, just reaching the surface of forehead ; anterior 

 frontals narrow, small, short ; posterior ones much larger, qua- 

 drangular ; vertical moderate, as broad as long, similar to the 

 same shield in L. nebulatus ; occipitals rounded behind ; nostril 

 between two shields ; loreal and ante -orbital generally united, as 

 in the just mentioned species ; but one of our specimens exhibits 

 on both sides a small, triangular, separated ante-orbital in the 

 lower front angle of eye ; another specimen has an ocular above 

 and beneath the loreal shield ; two posterior oculars ; generally 

 seven upper labials, the fourth of which is just below the eye ; it 

 is divided into two in specimens exhibiting eight upper labials. 

 One rather large temporal shield in contact with both oculars ; 

 four or five smaller ones, scale-like behind ; there are nine pairs 

 of lower labials, first pair forming together a suture, second, third 

 and fourth rather broad (in L. nebulatus very narrow) ; the chin- 

 shields, as above mentioned, give a sufficient character for distin- 

 guishing at once the species from L. nebulatus. Scales in fifteen 

 rows, those of the vertebral line six-sided, larger ; ventral plates 

 rather rounded, on the posterior part of body raised on the side ; 

 anal entire. Teeth equal, smooth. In coloration similar to L. 

 nebulatus, but with certain differences. Brownish grey, minutely 

 punctulated with brown ; on each side of body, black, yellowish- 

 edged cross bands, not extending on the belly, either alternate 

 with those of the other side, or confluent with them ; on the an- 

 terior part of trunk the bauds are enlarged to four rhombic spots ; 

 head symmetrically marked with brown ; belly yellowish, on each 

 side a series of small brown spots. In the stomach of specimen a, 

 I found a Veronicella. Length of tail 4" ; total length 19". 



3. Leptognathus variegatus. 



Dipsas variegata, Schley. Leyd. Mus. Leptognathus variegatus, 

 Dum. Sf Bibr. p. 4/7- 



Body compressed ; loreal none ; ten or eleven upper labials ; 

 one anterior ocular. Whitish, variegated with brown and with 

 broad brown transverse bands. (Dum. § Bibr.) Surinam. 



4. Leptognathus pavoninus. 



Dipsas pavonina, (Cuv.) Schley. Ess. ii. 280. Leptognathus 

 pavoninus, Dum. Sf Bibr. p. 474. 



Body slender, compressed ; loreal none; two anterior oculars, 

 ten or eleven upper labials. Above dirty white with a series of 

 large brown spots, regularly rounded on the posterior part of 

 body. (Dum. Sf Bibr.) Guiana. 



