158 
ON THE PHYSIOONOMY OF SERPENTS. 
nated ; colour of a clear brown, passing to yellow on the 
lower parts ; form less slender than usual ; belly slightly 
angular. S. 1484-136. 
3. Dryiophis prasina. Head conical ; muzzle trun- 
cated ; rostral plate with salient edges ; labials very deep 
grooved teeth very large; scales smooth. S. 200 + 160. 
Native of Bengal, Cochin-China, Java, Sumatra, and 
Celebes : the individuals of this latter isle form a variety 
with more slender tail. 
B. The Pseudo-Dry lophis or Dryiophis of the New 
Worldj with the teeth less developed, and pupil orbicular. 
5. Dryiophis Catesbyi. Colour green ; scales cari- 
nated ; muzzle very compressed and very obliquely trun- 
cated at the point. S. 204+140. From Cayenne to 
Florida. 
6. Dryiophis argentea. Form more delicate than 
usual ; six plates on the upper lip ; smooth scales. Colour 
silvery-white, speckled with a darker tint, and adorned on 
the sides and below with broad longitudinal rays of deep 
blue. S. 200 + 90. Inhabits Cayenne. 
7. Dryiophis aurata, has a form more light still than 
the preceding ; all the parts extremely delicate. S. 
190 + 162. Of a fine gilded bronze colour, dotted with 
black and white. Found from Brazil to Mexico, and per- 
haps also in Florida. 
BIPSAS. 
The tree-snakes, in the genus Dipsas, are recognisable 
by their very thick, broad, and obtuse heads, their vigor- 
ous, but compressed, trunk, the pupil ordinarily vertical, 
&c. They have, however, the elongated form peculiar to ani- 
mals of this family. Their scales are generally smooth and 
lanceolate ; and we observe in many species, a dorsal range 
of plates, larger than the rest ; the plates of the head 
very aggregated ; abdomen convex ; nostrils very open. 
Sometimes we find in the jaw a posterior grooved tooth. 
The Dipsas inhabits, by preference, the vast forests of 
Asia and intertropical America. Other parts of the world 
