ON THE SNAKES OF NORTH-EAST AFRICA. 641 



46. A List of the Snakes of North-East Africa, from the 

 Tropic to the Soudan and Sonialihand, including 

 Socotra. By G-. A. Boulenger, F.R.S., F.Z.S.* 



[Received Octobei- 4, 1915 ; Ueiid November 23, 1915.] 

 Index. 



CtEOGllAPHlCAL : Page 



N.E. Africa, List of Snakes 641 



Systematic : 



Keys to the ideutiticatioii of the Snakes of N.E. Africa 641 



With this Kst the Ophidian fauna of East and Central Africa 

 is completed, only two divisions remaining to be dealt with, 

 viz., West Africa north of the Congo, and North Africa. 



/Synoj:>sid of the Families. 



I. Worm-like, with small inferior mouth ; eyes hidden or visible under the head- 

 shields, and body covered with uniform imbricate scales above and beneath. 

 22 or more scales round middle of body ; ocular not bordering the 



mouth; tail not or but little longer than broad Typhlopid.i;. 



11 scales round middle of bodj' Glauconiiujj. 



II. Mouth large, eyes exposed; body with enlarged shields beneath (except in 

 the marine genus Sydrus). 



Ventral shields much narrower than the bod}^ ; supraocular, if 

 distinct, broken up into two or more shields; scales on 

 anterior part of body smooth Boidje. 



Ventral shields at least nearly as broad as the body ; supraocular 



single; poison-fangs, if present, not ni a very large sheath ... Colubriu.t^. 



Ventral shields at least nearly as broad as the body, or upper sur- 

 face of head covered with small scales ; poison-fangs in a very 

 large sheath below the eve VirEiUDi\ 



A single genus. 



Family T v p h L o p i u .-E. 



1. Typhlops. 

 Schneid. Hist, xlniph. ii. p. 339 ; Bouleng. Cat. Sn. i. p. 7. 



S'l/uopsis of the Species. 



I. Snout rounded or with obtusely angular horizontal edge. 



A. Rostral not more than one-third width of head ; eyes distinct. 

 Snout rounded ; 24 scales round middle of body, the diameter of 



which is 37 to 50 times in total length T. socotranus. 



Snout much depressed ; 22 scales round middle of body," the 



diameter of which is 20 to 30 times in total length T. ouiieirostris. 



13. Rostral very broad. 

 Rostral half width of head ; 30 scales round middle of body, the 



diameter of'which is 30 to 40 times in total length T. hlanfurdu. 



Rostral more than half width of head ; 26 to 30 scales round 



middle of body, the diameter of which is 24 to 30 times in 



total length T. puuctatics. 



* Published by pei'niission of tlie Trustees uF the IJritish jMuseuui. 



