42 
NATURAL HISTORY. QUPPER FLOOR. 
these the True Vipers ( Viper as ) are distinguished by the 
head being covered with scales like those on the back, 
and by the nostrils being very large. Amongst these there 
are the Nose-horn Viper ( Coluber nasicornis), peculiar for 
two horns on the end of the nose; the Cerastes ( Coluber 
cerastes ), the male of which has a long horn-like scale 
over each eye, which being absent in the female, has caused 
the latter to be erroneously described as a distinct species; 
the Puff Adder, or Short-tailed Viper ( Vipera injlata), 
the most deadly snake of the Cape; and Russel's Viper 
(■Coluber Russell ). 
The Adders ( Bert ) have the head covered with granular 
scales, and the nostrils moderate; as the Black Adder 
('Coluber berus), and the Ammodyte Adder ( Coluber am - 
modytes) from the shores of the Mediterranean, very pecu¬ 
liar for the end of the nose being lengthened into a flexible 
horn. 
The Common Adder ( Coluber chericus) differs from these, 
by the crown of the head having three larger scales in¬ 
serted amongst the smaller ones; this is the only reptile 
found in Great Britain possessed of dangerously poisonous 
qualities. 
The Cylindrical Snakes differ from the other venomous 
reptiles, by the head being much smaller, scarcely so broad w 
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 extension 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 spectacles. These 
snakes are used by the native jugglers in their exhibitions. 
The Coral Snakes ( Elapses ) 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 cor allinns . 
The Flat-tailed Coral Snake ( Platurns ) found in the 
Indian Seas, differs from the other Coral Snakes, by its 
tail being flattened like the Sea-Snakes. 
Cases 7—13 contain those snakes which have a regular 
row of teeth on the edge of the upper jaw; most of wdiich 
