IN^NOGUOUS SERPENTS. 
149 
HERPETODR YAS 
Is the sixth genus of Plarmless Terrestrial Snakes. They 
prefer to live in woods, or usually frequent trees. They 
approach the genus Coluber in organization ; but they 
have a more slender shape, their head is more elongated, 
and the greatest numbers present a livery of green, more 
or less uniform. Their habits are wild ; they inhabit the 
warm districts of both worlds, but they have never yet 
been found in Africa, nor in New Holland. Europe and 
Japan do not furnish one species. Most of them feed on 
birds. 
1. Herpetodryas carinatus. a serpent remarkable 
from its back being furnished with two rows of scaly plates 
along its ridge, making the whole rows of scales an even 
number, an instance unique in all the order of Ophidians. 
It is also remarkable, because all the parts are liable to 
considerable variations. The rows of scales are twelve, 
and the two dorsal rows are often surmounted by a strong 
keel. The scuta vary from 142 + 98 to 199 + 104. We 
find in this species several distinct varieties marked by 
their shape being more or less slender. Above brown, 
verging on green, on greyish-black, or on red ; the back 
more clear ; below yellow. Inhabits Brazil, and is very 
common in Surinam. Arrives at the length of six feet. 
2. Herpetodryas Serra. A very rare species from 
Brazil. Shape thin, trunk strongly compressed, back 
carinated, tail slender, abdomen angular, frontal plates 
narrow, scales strongly carinated, lanceolate, and disposed 
in twenty-one rows. PL 241 + 106. The last maxillary 
tooth long and grooved. A series of large square dorsa’ 
spots on a pale reddish-grey ground, which, on the tail, 
passes into black, 
3. Herpetodryas viridissimus. — Head broad and 
compressed ; abdomen very angular ; nineteen rows of 
scales, with smooth and very shining surfaces. Size from 
two to three feet. Colour above, bluish-green, more clear 
below. S. 215+115. Inhabits Surinam. 
4. Herpetodryas Olfersii. — Form less slender than 
the former; the last labial plates broad ; colour green; 
