INNOCUOUS SERPENTS. 
127 
we may particularly observe, that the former exclusively in- 
habit the sea or the land, that they do not climb trees, 
and that they never frequent fresh water, with the excep- 
tion, perhaps, of some species of Naja. 
INNOCUOUS SERPENTS. 
In distributing the Serpents not venomous into families, 
I have chiefly kept in view their mode of living. Those 
sections which have little importance as regards organiza- 
tion, have only been adopted for the purpose of facilitating 
a review of species. 
The First Family comprehends the Burrowmg Snakes, 
the only genus of which is the 
TO RTRIX. 
Wemay assign to them as distinctive marks — acylindric 
body, with almost the whole trunk of the same dimen- 
sions ; a short and conical tail ; a small obtuse head, of 
the same diameter as the trunk, and covered with plates 
imperfectly developed ; small eyes ; narrow nostrils ; a 
mouth but little cleft ; the tympanites very massive ; the 
teeth short and conical ; in fine, a certain resemblance to 
the Amphisbmna and Typhlops. The Tortrices often exhi- 
bit hooks at the anus ; they inhabit hot countries in both 
worlds, they never leave the ground in which they dig 
burrows. We only know five species. I place at the 
head of the genus — 
1. Tortrix Scytale of Surinam, remarkable by its 
slender trunk, filiform and ringed with black and red ; the 
eyes are placed in the centre of the ocular plate ; the short 
tail is very obtuse ; it sometimes grows to the length of 
3 feet ; scuta 225 + 12. The second species,f 
2. Tortrix rufa comes from Java and Celebes, where 
* The Trigonocephalus viridis is an exception to this rule, in so 
far as it has the habit of attaching itself by its prehensile tail to branches 
of shrubs, to watch for its prey. 
t [M. Schlegel always indicates the number of abdominal and sub- 
caudal scuta by this symbol ; the first number being the abdominal, the 
latter the subcaudal, with the sign + (pZ^^sJ^^etween the numbers. — Tr\] 
