PUFF-ADDERS. 



89 



sionally the spots forming the middle row are connected like the 

 beads of a necklace, whence the name Cobra monil (literally 

 Coluber moniliger), applied to the young of this Viper by the Indo- 

 Portuguese, and now corrupted into " Cobra de Manilla/' which 

 bears the reputation of being a highly poisonous Snake of diminu- 

 tive size ; it attains, however, to a length of nearly five feet, the 

 tail then measuring about eight inches, with considerable thick- 

 ness of body. It is nocturnal, and preys chiefly on Mice. In Burmah 

 this ^formidable Yiper is dreaded almost as much as the Hama- 

 dryas. It has been obtained in the Himalayas at an elevation of 

 5,500 feet, at Almorah, and elsewhere. Mr. Theobald has known 

 one to kill a Bull-terrier in twenty minutes. The D. xanthina is 

 a second species of this form inhabiting Asia Minor. 



The genus Clotho consists of the terrible Puff-adders of Africa, 

 of which there are at least four or five species. Among the best 

 known of them are the ordinary Puff-adder (C. arietans), and the 

 Berg-adder (C. 

 atropos), of the 

 Cape colonists. 

 The Rhinoceros 

 Puff-adder, C. na- 

 sicornis, of Guinea, 

 has the scales over 

 the nostrils of the 

 male produced into 

 a long recurved 

 spine ; and in the 

 Horned Puff-ad- 

 der, C. cornuta, of 

 South Africa, there 

 * is a group of small 

 horn - like scales 

 over each eye. 

 Examples of the 



Common and of the Rhinoceros Puff-adders may generally be 

 seen in the reptile house of the London Zoological Gardens. The 

 last mentioned is a huge Yiper of wondrous beauty, both of 

 colouring and in the complex pattern of its markings, especially 



Fig. 21. The Horned Puff-adder (Clotho cornuta). 



