CROTALIDiE. 
The family of Crotalidce or Pit-Vipers has several genera in 
British India. I have before observed that they are not so 
dangerous as their American congeners, though all are veno¬ 
mous.* They are distinguished, as has been already stated, 
by the pit or depression between the eye and the nostril, in the 
loreal region; the triangular broad head and the short thick 
body. The Ilalys is the only Indian genus or species that 
has any vestige of the caudal appendage which has given to 
some of the American Crotalidce the name Rattlesnake ; and in 
this species it is reduced to a simple horny spine at the end of 
the tail. 
Many of the Indian Crotalidce are arboreal snakes, and in colour 
resemble the foliage or branches of the trees in which they live. 
The Crotalidce are considered by naturalists generally, I 
believe, to be viviparous, but I have recently been informed that 
Mr. Nicholson of Rangoon says that the Trimeresuri are 
oviparous, and that eggs have been removed by him from the 
body containing no appearance of an embryo; which would 
imply that the eggs would be laid, and the young developed 
like those of the colubrine snakes. 
It is probable that they are ovo-viviparous, and the question 
of the liberation of the young from the egg before or after its 
extrusion from the oviduct, is not one of great physiological 
importance, though interesting enough as a fact in the natural 
history of the individual genus or species. The generic distinc¬ 
tions of the Crotalidce are described by Gunther as follows :— 
“ Body robust; tail of moderate length or rather short, some¬ 
times prehensile; head broad, sub-triangular, frequently scaly 
above or imperfectly shielded; a deep pit ” (the use of which is 
not known), “ on the side of the snout, between the eye and 
nostril; eye of moderate size, with vertical pupil. Viviparous.” 
There are several Indian genera:— 
Trimeresurus 
Peltopelor 
Ilalys 
Hypnale . 
T. gramineus. 
T. erythrurus. 
T. carinatus. 
T. anamallensis. 
T. monticola. 
T. strigatus. 
T. mucrosquamatus. 
T. andersonii. 
P. macrolepis. 
H. himalayanus. 
H. or Trigonocephalus elliotti. 
H. nepa. 
TRIMERESURUS. 
Gunther’s definition of this genus is the following :— 
“Head triangular, covered above with small scales, except the 
foremost part of the snout and the supraciliary region, which 
generally are shielded; body with more or less distinctly keeled 
scales, in from seventeen to twenty-seven series. Body and tail 
of moderate length, prehensile. Sub-caudals two-rowed.” 
These snakes are fierce and venomous, but very few deaths 
aie ascribed to their bites. Some of the Trimeresuri attain to 
* The Calloselasmci rhodostoma, found in Java and Siam, is said to he very 
deadly Kuhl, as has been before mentioned, saw two men bitten by the same 
snake die in five minutes. 
a considerable size : a T. carinatus from the Indian Museum, 
captured at Port Canning near Calcutta, is 36 inches in length 
and nearly 4 inches in circumference, and is a much more 
powerful snake than a Bungarus cceruleus for example, now in 
my possession, 31 inches in length and 2J in girth, which killed a 
dog m less than thiee hours, and a fowl m three or four minutes. 
The fangs of the Trimeresuri are long, and capable of inflict¬ 
ing a deep puncture; it cannot therefore be the small size of 
the snake or of its poison fangs that makes it less deadly : this 
is doubtless due to a less virulent venom. 
I am compelled to differ from Dr. Gunther when he says, 
“ The degree of danger depends but little on the species which 
has inflicted the wound, but rather on the bulk of the individual, 
on the quantity of its poison, on the temperature, and on the 
place of the wound;” for though there can be no doubt that 
all the conditions he enumerates—size, quantity of poison, 
state of the snake at the time of inflicting the wound, tempera¬ 
ture—have much influence on the action of the poison, yet, 
quantity for quantity, the poisons of different genera, even 
species, vary considerably in intensity. My experiments, as far 
as they go, seem to show that in equal quantities the poison of 
the Cobra is more active than that of the Hamadryad, which is 
three times its size.* That of the Bungarus ccerideus is more 
deadly than that of the Bungarus fasciatus, which is much larger. 
That of the Daboia is perhaps equal or little inferior to that 
of the Cobra, and is far more deadly that the venom of the 
Bungarus fasciatus, perhaps of the Bungarus cceruleus, and JEcliis, 
and if we may depend on what is recorded, than of the 
Trimeresuri. My impression is, that of all the Indian terres¬ 
trial Thanatophidia, the Cobras stand first in the scale of de¬ 
structiveness ; the Daboia next; then the Hamadryad; next 
the Bungarus ccerideus ; then the Bungarus fasciatus and JEcliis, 
the Crotalidce and Callophides. My own experience has been 
chiefly confined to the Cobra, Hamadryad, Bungarus fasciatus, 
Bungarus cceruleus, Daboia, Echis, and certain Hydrophidce, 
but from what I have read and heard from others, I gather 
that the Callojohides and the Crotalidce of British India come 
last in the scale. I exclude the Ilydrojchidce for the present; 
these remarks applying chiefly to the terrestrial poison snakes. 
I am aware that it is stated on high authority that the Callo- 
selasma rhodostoma, a comparatively small species, attaining to 
three feet in length, of a genus of the Crotalidce, and found in 
Siam and Java, is very deadly; but so far as I know there is 
not so deadly a member of the family of Crotalidce in Hindostan. 
Further experiments will, however, I hope, enable me to speak 
more positively on this important point in the natural history 
of the Thanatophidia. Cantor,f Jerdon, Russell, and others 
who have experimented with the Trimeresuri, say that the 
The Rev. Mr. Vinton, Karen Missionary in Rangoon, who has experimented 
frequently with the poisonous snakes of Burmah, says that he is convinced that the 
venom of the Ophiophagus is less deadly in equal quantities than that of the Cobra. 
The Ophiophagus is more dangerous on account of the greater quantity of venom, 
and the pertinacity with which, when disturbed, it maintains its hold, apparently 
with the view of injecting as much of the poison as possible. 
f Cantor says of the Trimeresuri : “Although the genus has venomous organs 
as highly developed as Crotalus or Vipera, the effect produced by wounds of two 
species at least appears to be less dangerous than might be d priori supposed.”_ 
Journal As. Soc. Bengal, vol. xvi. p. 1045. 
According to Russell’s experiments with the venom of T. gramineus, chickens 
expired within eight to thirty-three minutes, pigeons in fourteen to eighteen 
minutes; a pig recovered in six to seven hours; a dog in two to three hours, after 
emg wounded (Russell, vol. i. p. 60). Mr. Hodgson has seen a man who was 
