ill the Collection of the British Museum. 421 



Gerarcla hicolor (Gray). 

 This snake is not from the West Indies, but from Pegu, 

 where specimens were collected by Mr. Theobald. 



Hydrops Martii (Wagl.). 



Hygina fasciata, Gray. 



Scales constantly in fifteen series. 



Hydrops callostictus. PI. XVII. fig. B, 



Scales in seventeen rows. Anterior frontal nearly twice as 

 broad as long ; occipitals as long as the vertical and frontals 

 together ; two postoculars ; eight upper labials, the fourth en- 

 tering the orbit ; the second upper labial in contact with the 

 posterior frontal; loreal none; temporals 1 + 1. There are 

 four lower labials, in contact with the front chin-shields. Ven- 

 trals 168 ; anal bifid ; subcaudals 90. The upperside of the 

 head and of the back reddish olive. Sides and belly of a 

 lighter colour, approaching to white ; body and tail encircled 

 by numerous black rings, each about two scales broad and 

 edged in front and behind by pearl-coloured dots ; the bands 

 are frequently broken on the median line of the back and 

 belly. Snout black, with a yellow band across the prefrontal; 

 temple black, separated from the first black ring by a yellowish- 

 white cross band. 



One specimen, 11 inches long, was found by Mr. Bartlett 

 at Chyavetas (Upper Amazons) . 



MiMOPHiS (g. n. Psammophid.). 



Body and tail moderately slender, scarcely compressed; 

 form of the head as in PsammopMs, but with the loreal region 

 less distinctly grooved; rostral shield not enlarged; eye of 

 moderate size, with round pupil; nostril small, placed in a 

 single shield, behind which is another small shield; loreal 

 none, replaced by the posterior frontal, which is bent down- 

 wards on the sides ; scales smooth, with one apical groove, in 

 seventeen rows, those of the vertebral series not enlarged; 

 ventrals not keeled ; anal and subcaudals bifid ; the third or 

 fourth maxillary tooth enlarged ; posterior maxillary tooth 

 grooved ; front teeth of the lower jaw larger than the pos- 

 terior. 



This genus bears a similar relation to Psammojyhis as Tro- 

 pidococcyx to Tragops, and illustrates in some measure the 

 affinity between the Dryophidce and Psammophidm. 



Mimophis madagascariensis. PI. XVIII. 

 In habit very similar to Psammophis sihilans. Snout 



