47 
The Common Adder (Coluber cherica) differs from 
these, by the crown of the head having three larger scales 
inserted amongst the smaller ones ; this is the only rep¬ 
tile found in Great Britain possessed of dangerously 
poisonous qualities. 
The Cylindrical Snakes differ from the other venom¬ 
ous reptiles, by the head being much smaller, scarcely 
so broad as the body, covered with large regular 
plates, and without any pit on the cheek. Some of 
these, as the Spectacle Snake or Naja, have the 
faculty of dilating the skin of the neck, by the ex¬ 
tension of their ribs, so as to form a kind of hood over 
the head; they are also peculiar from the body being 
covered with very narrow scales. 
The Indian species have usually a yellow spot on the 
back of the neck, somewhat resembling a pair of spec¬ 
tacles. These snakes are used by the jugglers, in their 
exhibitions. 
The Coral Snakes (Elaps) are very similar in form, 
but the neck is not dilatable, and the dorsal scales are 
broad ; many of these are marked with black and 
bright coloured bands, as Elaps corallinus. 
The Flat Tailed Coral Snake (Platurus) found in 
the Indian Seas, differs from the other Coral Snakes, 
by its tail being flattened like the Sea-Snakes. 
Cases 7 —IS contain the snakes which have a regular 
row of teeth on the edge of the upper jaw. Most of 
these have long conical tails, and broad plates under the 
abdomen. These species are, in general, innocent; a 
few have some of the upper lateral teeth rather larger 
than the rest, and grooved on the hinder edge, the 
groove communicating with a gland placed on the side 
of the face, but their bite is seldom so dangerous as 
that of the other snakes which have only large fangs in 
the upper jaw. The species of this division are exceed¬ 
ingly numerous and difficult to determine, and they 
have lately been divided into many genera, which it 
would be tedious to characterize in this sketch. Those 
which 
ROOM X. 
Nat. Hist. 
