192 
ON THE PHTSIOONOMY OF SERPENTS. 
also found in Northern Africa. Greyish or yellowish 
brown, has rays and ocellated spots on the upper parts. 
5. ViPERA Cerastes. — Conspicuous by its very broad 
heart-shaped head ; by its short, obtuse, and rounded 
muzzle ; by the nostrils very narrow, vertical, and placed 
at the tip of the snout ; by its scales, surmounted by a keel, 
in the form of a tubercle ; by its pale tints, greyish or earth- 
coloured ; and, lastly, by the development of the super- 
ciliary scales, one of which is often converted into a point 
of considerable length. S. 134 + 29. Inhabits the deserts 
of Northern Africa. 
6. ViPERA ELEOANS. — Form more than usually slen- 
der ; eye protected by a superciliary plate ; nostrils very 
open, lateral ; muzzle narrow, drawn out, and angular 
at the sides; of large size. S. 168 + 52. Comes from 
India and Ceylon. Bright yellowish-brown, with 3 rows 
of oval spots, bordered with black, and white on the lower 
parts. 
7. ViPERA Berus. — The Common Viper of the north 
and centre of Europe, is also disseminated over a great part 
of Asia. Middle size ; top of head invested with plates, 
among which we distinguish a vertical, superciliaries and 
two occipitals ; muzzle rounded, and angular at the sides ; 
nostrils wholly lateral. S. 145 + 35. Varies from brown 
and grey, to black and red ; a broad zig-zag ray along the 
back. The males have the brightest tints. 
8. ViPERA Aspis. — Takes the place of the last, which 
it nearly approaches, in the south-east of Europe, and is 
also found in Sicily. Form rather more slender; head 
larger, covered above with scales of an irregular form ; 
muzzle a little turned up ; body with several rows of spots. 
Varies like the last. S. 152 + 42. 
9. ViPERA Ammodytes. — Nearly allied to the two last 
by habit and physiognomy ; but it has a thicker shape, a 
muzzle prolonged in a point directed upwards, the summit 
of the head very irregularly covered with scales and small 
plates. S. 150 + 34. System of colours nearly as in the 
Common Viper, but it often has the tail reddish. Inha- 
bits the south-east of Europe, from Sicily and Dalmatia 
to Greece. 
