SNAKES. 55 
two posterior oculars: lower lip edged with a series of triangular 
scales. 
a. In spirits. India. Presented by the Zoological Society. 
t+ Scales rather elongate, tubercularly keeled. 
12. The Roven Sea Snake. Hydrophis aspera. 
Pale: back with lozenge-shaped cross-bands : tail dark: scales 
with a strong short keel, with two or three tubercles on it; of the 
front part of body lanceolate, and the hinder part and under-side 
broader: ventral shield (of two united scales) from the throat, with 
two distinct tubercular keels: head moderate, short, thick; head 
shields granular: one anterior and two posterior oculars: lower la- 
bial shields small, triangular, with band-like shield between them: 
upper labial shields moderate ; second largest; sixth small, trian- 
gular, with a rather large shield above it: chin shields one pair, 
moderate. 
a. In spirits. Singapore? From Mr. Gardenet’s collection. 
1. Hydrophis striata, Bote, Faun. Japon. t. 7; Schlegel, Phys. 
Serp. 502, t. 18, f. 4, 5, may be intended for this species; but 
Schlegel’s description is so general that it rather fits the genus than 
any particular species. 
2. Hydrophis hybrida, Schlegel, Abbild. 115, t. 37, appears also 
to be allied to this species: perhaps a variety, with the dorsal spot 
smaller. 
13. The Biuish Sea Snake. Hydrophis cerulescens, Gray, 
Zool. Mise. 6. Hydrus cerulescens, Shaw, Zool. iii. 561. | Enhy- 
dris cerulescens, Merrem, Tent. 140. 
Above blackish ash in spirits, beneath whitish ; side of the neck 
and base of the tail with white bands, of the body with roundish 
white spots; tail blackish ash: scales elongate, six-sided, with short 
subcentral tubercle-like keel; of the front of the body narrow, lance- 
olate, and the hinder part and under-side broad: ventral shields from 
neck with two short slight keels: head shields tubercular : lower ros- 
tral shield trigonal, sub-equilateral : the first, second and third lower 
labial shields large ; fourth small, triangular, with large plates below 
it: chin shields one pair, moderate. 
a. In spirits. Indian Ocean. Specimen described by Dr. Shaw. 
H. cerulescens, Shaw. 
b. In spirits. India, Bengal. 
