564 A, Alcock & F. Finn — Afghan- Balnch RepHUa. [No. 4, 



Family Viperidae. 

 Eristicophis, n. gen. 



Head very distinct from neck, covered with small feebly-imbricatd 

 scales : eye small, with vertical pupil, separated from the labials by 

 small scales : nostril directed upwards and outwards, forming a valve- 

 like slit at the summit of an enlarged nasal, the nasal separated from 

 the rostral by an enlarged rostro-nasal shield. Body cylindrical, scales 

 in 23 to 24 rows, with simple (i.e., non-serrated) keels, the keels not 

 extending to the tip of the scales : lateral scales varying in size, not or 

 hardly smaller than the dorsals, and hardly oblique : ventrals with a 

 well-defined keel on either side. Tail short, sub-caudals in two rows* 



In Mr. Boulenger's Key (Cat. Snakes Brit. Mus. Vol. III. p. 465) 

 this form finds a place in Section 11, with Vipei'a, JEJchis, Cerastes, &c. 

 It does not, however, fit into any of the three sub-sections of the Key ; 

 since, while it has the lateral scales not, or not noticeably, smaller than 

 the dorsals, and the keels of the scales not serrated, and the sub caudals 

 in two rows, it has the ventrals angulate laterally— more sharply 

 angulate even than Cerastes. 



We are indebted to Mr. Gr. A. Boulenger, F-.R.S , for the opinion 

 that this Viper is worthy of generic rank. 



We are also much indebted to Mr. Boulenger for facilities afforded 

 to one of the authors of this paper for comparing specimens. 



30. Tjristicopliis Macmahonii, n. sp. Plate XV. 



Snout square, even emarginate by reason of the projection of its 

 wing-like angles and of the slight dorsal concavity of the middle line. 

 The rostral region is covered by 5 scales, the surfaces of none of which 

 are visible from above : these scales are disposed as follows :— (I ) a 

 true rostral bounding the mouth, concave, horse-shoe-shaped, from two 

 to three times as broad as high ; (2) above and on either side of 1, a 

 pair of pear-shaped scales with projecting edges and concave surface, 

 forming the wing-like angles of the snout; (^) between 1 and 2, a pair 

 of little scales hardly differing from those that form the general invest- 

 ment of the head. The tips of these last are sometimes visible from 

 above. 



Nostrils large, valvular, directed upwards and backwards, pierced 

 in the npper and posterior angle of a large nasal. 



Scales of the head hardly imbricate, strongly carinate, none of them 

 enlarged except one above either nostril and one at either outer angle 

 of the snout ; in thirteen or fourteen very irregular rows between the 

 eyes : four series of scales between the eye and the upper labials : at 

 least five rows of scales between the nostril and the eye. 



