192 ON THE PHYSIOGNOMY 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. 134-1- 29. Inhabits the deserts 

 of Northern Africa. 



6. ViPERA ELEGANS. — Fomi morc than usually slen- 

 der ; eye protected by a superciliary plate ; nostrils very 

 o]ien, lateral ; muzzle narrow, drawn out, and angular 

 at the sides; of large size. S. 168-1-52. Comes from 

 India and Cevlon. Bright vellowish-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 gi'eat 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 -f 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 4-34. 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. 



