504 SNAKES OF CEYLON. 



Supralabials : Six to thirteen ; the anterior one or two 

 touching the nasals, none touching the eye, being separated 

 from it by from one to three rows of scales. Sublinguals : 

 One pair ; in contact with three or four infralabials. Infra- 

 labials : Three or four. 



Costals : Longer than broad, rectiform ; keeled ; with or 

 Without apical pits. Vertebrals not enlarged. Ultimate row 

 enlarged, its scales twice or more than twice the breadth of 

 the vertebrals. In 19 to 33 rows in midbody, often two less 

 two heads -lengths behind the head, and from four to eight 

 less two heads-lengths before the Vent. Supracaudals : In 

 even rows. Ventrals : 120 to 180; rounded. Anal: Entire. 

 Subcaudals : 20 to 65 ; divided. 



Dentition (in Asiatic species). — Maxillary : Two canali- 

 culate fangs placed side by side. Palatine : Anododont, 

 isodont ; with an edentulous space anteriorly, or posteriorly, 

 or both. Pterygoid : Anododont, isodont ; posterior half 

 edentulous. Mandibular : Anododont, scaphiodont. 



Distribution. — There are ten species inhabiting Europe, 

 Asia, North and Tropical Africa. Only one of these occurs 

 in Ceylon, viz., V. russelli. 



Vipera russelli (Shaw). 



(Named in honour of Patrick Russell.*) 



Russell's Viper or the Daboia. 



Sinhalese : " tic polonga " (spotted snake). Tamil 

 " kanardi viriyan" (spectacle snake). 



Synonymy. — Coluber russellii, G. trinoculus, C. triseriatus, 

 Vipera elegans, Daboia elegans, D. russellii, D. pulchella, 

 Echidna elegans, E. russellii. 



* This title commemorates the name and fame of Dr. Patrick 

 Russell, a distinguished savant, and the pioneer of all snake research 

 work in India, both in its zoological and toxicological aspects. He was 

 born ill Edinburgh in 1726, and came out to India in 1781. Four years 

 later the Honourable the East India Company appointed him their 

 naturalist. He is responsible for a monumental work on the Indian 

 snakes, with excellent coloured plates, in two volumes, published in 

 1796 and 1801. The association of his name with this common snake, 

 renowned as much for the beauty of its colour and ornamentation, as 

 for the deadly character of its bite, is a fitting tribute to his classical 

 work. 



