THE THANATOPHXDIA OF INDIA 
SECTION I. 
ZOOLOGICAL AND ANATOMICAL CHARACTERS, HABITS, AND DISTRIBUTION. 
The Inspector-General of Hospitals, having at my request 
sanctioned the distribution among Medical Officers in the 
Bengal Presidency of a circular letter* and printed form, with 
the object of obtaining information on the subject of snake¬ 
poisoning in the Presidency, I think it may be well to supple¬ 
ment that circular with a short description of the list of 
poisonous snakes thereunto appended, and with a few remarks 
on some important anatomical and zoological peculiarities of 
these reptiles, as it may be useful to those who have not paid 
particular attention to this branch of Natural History. 
The list, in giving merely the names of the varieties, species, 
and genera of the Thanatophidia, or poisonous snakes, indicates 
generally the localities where they may be looked for, and the 
relative frequency or rarity in which they may be expected to 
occur. A more detailed account may, perhaps, aid those who 
are disposed to assist in collecting and recording reliable infor¬ 
mation on a subject interesting alike to science and humanity. 
The order Ophidia, of the sub-class Reptilia proper, is divided 
into three sub-divisions :— 
1. Ophidii Colubriformes, innocuous snakes. 
2. Ophidii Colubriformes Yenenosi, or poisonous colubrine 
snakes. 
3. Ophidii Viperiformes, or viperine snakes—poisonous. 
The two last sub-orders, under the designation of Thanato¬ 
phidia, a name peculiarly applicable to them, as they occur 
in India and in the Bengal Presidency especially, I propose to 
describe. 
I will premise the description of individual genera and 
species by a few remarks on the general characteristics of the 
three sub-orders, and especially on those which distinguish 
the innocuous from the venomous snakes ; and of the latter, 
the differences which mark the viperine from the colubrine 
forms. 
The characters possessed in common by the three sub-orders 
are the elongate form ; the absence of any exo-skeleton, sternum, 
pectoral arch, sacrum or limbs, with the exception in a few of 
the Colubrines, of rudimentary pelves, or hinder extremities. 
The mandibles are united by an extensible ligament, and are 
articulated with tympanic hones, which allow of the extensive 
gape through which the snake swallows its prey. Snakes have 
neither external ears nor eyelids, but the eye is covered 
by a transparent glassy capsule, which exfoliates with the 
epidermis, when that is shed. The body is naked, but it has 
this epidermis, which is frequently exfoliated, laid in scale-like 
folds and shields on the head and ventral surface. The number 
and arrangement of these non-imbricated shields on the head is 
of value in the classification of the genera and species. They 
are named as follows :— 
* Vide Appendix, No. 1. 
Ocular anterior, or prse-orbital. 
,, posterior, or post-orbital. 
Upper labials. 
Temporals. 
Mental. 
Lower labials. 
Chin shields. 
Rostral. 
Anterior frontal. 
Posterior frontal. 
Vertical. 
Supra-ciliary. 
Occipital. 
Nasals. 
Loreal. 
Snakes are provided with sharp, recurved teeth which are 
anchylosed to the maxillary, palatine, and pterygoid bones, 
and it is by the form and arrangement of these teeth that the 
poisonous are most easily distinguished from the innocuous 
species. Certain Ophidia approaching nearly to the Saurian 
forms, such as the Typlilopidce, Tortricidce, TJropeltidce, have 
rudimentary pelves and a narrow mouth, without the enormous 
gape; but in these it is only a matter of less development. 
The lungs are unsymmetrical, one being much larger than the 
other. The heart has three cavities, one ventricle and two 
auricles ; the urinary bladder is wanting. 
The organs of locomotion are the ribs, which articulate with 
rudimentary transverse processes of the vertebrae, and correspond 
nearly to the number of dorsal vertebrae, and the ventral plates 
or scales. 
Snakes are all carnivorous, existing on living animals or eggs; 
the prey is swallowed entire, as they have no organs of masti¬ 
cation. They are oviparous, ovo-viviparous, or viviparous. 
They are “ hsematocrya,” or cold-blooded. Their blood is rich 
in solid constituents, and has red corpuscles of an elliptical 
shape, which are flattened and bi-convex, and smaller than in 
other reptilia. 
These are some of the most marked characteristics of the 
order Ophidia, that are common to the three sub-orders into 
which it is sub-divided. Before describing those which diffe¬ 
rentiate one sub-order from the other, I would make a few 
remarks on the osteology of the cranium, the dentition, and on 
the glandular apparatus, to which the venomous snakes owe 
their deadly properties. The Ophidia are distributed generally 
over the surface of the globe, wherever climate and other 
circumstances are favourable to their existence; India has 
perhaps a larger share than any other country, and the 
poisonous forms constitute a considerable proportion of the 
whole number of families. 
Of twenty-one families well known to naturalists, in this 
country, four are poisonous. The most deadly of the poisonous 
colubrine snakes—such as the Ophiophayus elaps, and JVaja 
tripudians— are Indian, whilst of the viperine forms, the 
Jiperidce are represented by the formidable Daboia russellii, 
than which there is probably no more deadly Viper, and the 
Crotalidce by the Trimeresuri. All the members of this 
family are much less formidable than their African and 
B 
