in the Collection of the British Museum. 421 
Gerarda bicolor (Gray). 
This snake is not from the West Indies, but from Pegu, 
where specimens were collected by Mr. Theobald. 
Hydrops Martti (Wag}.). 
Hygina fasciata, Gray. 
Scales constantly in fifteen series. 
Hydrops callostictus. Pl. 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 
hee iadl frontal; loreal none; temporals 1+1. There are 
our 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 
aie 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). 
-Mrvoruts (g.n. Psammophid.). 
Body and tail moderately slender, scarcely compressed ; 
form of the head as in Psammophis, 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 Psammophis as Tro- 
prdococcyx to Tragops, and illustrates in some measure the 
affinity between the Dryophide and Psammophide. 
Mimophis madagascariensis. P\. XVIII. 
In habit very similar to Psammophis sibilans. Snout 
