306 mr. a. a. boulenger on the 



2. Walterinnesia. 



Lataste, Le Natural. 1887, p. 411; Bouleng. Cat. Sn. iii. 

 p. 392. 



1. Walterinnesia .TiGYPTiA Lataste, 1. c. ; Bouleng. 1. c. 

 Egypt ?, Nubia ? 



Family ViPERiDiE. 



I. Lateral scales not smaller than dorsals, without serrated teels. 

 Nasal in contact with rostral or separated from it by a naso-vostral 



shield; scales in 19 to 27 rows Vipera. 



Nasal separated from rostral by small scales ; scales in 29 to 41 rows... JBitis. 



II. Lateral scales smaller than dorsals, disposed obliquely, with serrated keels. 



Ventrals angulate laterally ; subcaudals in two rows Cerastes. 



Ven trals rounded ; subcaudals single EcMs. 



1. Vipera. 

 Laur. Syn. Kept. p. 99 ; Bouleng. Cat. Sn. iii. p. 471. 



Two species : — 



Snout turned up at the end, produced into a small scaly appendage ; 



scales in 21 rows V. latastii. 



Snout rounded ; scales in 25 or 27 rows V. Ubetina. 



1. YiPERA LATASTII BoscA, Bull. Soc. Zool. France, 1878, p. 116,. 

 pi. iv. ; Bouleng. t. c. p. 484. 



Morocco and Algeria north of the Atlas, Spain and Portugal. 



2. Vipera lebetina. 



Coluber lebetinus Linn. S. N. i. p. 378. 



Vipera lebetina Bouleng. t. c. p. 487. 



Morocco, Algeria, Tunisia, S.W. Asia, Greek Archipelago. 



2. BiTis. 

 Gray, Zool. Miscell. p. 69 ; Bouleng. Cat. Sn. iii. p. 492. 



1. BiTIS ARIETAKS. 



Morocco (Valley of Sous), Tropical and South Africa, S. Arabia. 



3. Cerastes. 

 Wagl. Syst. Amph, p. 178 : Bouleng. Cat. Sn. iii. p. 501. 



Two species : — 



15 to 21 scales across the head, from eye to eye, 14 to 18 round the 

 eye ; frequently an erect horn-like scale above the eye ; .scales in 

 27-35 rows; ventrals 130-165 C. cornnfns, 



9 to 13 scales across the head, from eye to eye, 9 to 14 round the eye ; 



scales in 23-27 rows; ventrals 102-122 C. vipera. 



