510 



VIPEEIB*. 



This species is nearly completely connected with the preceding, 

 and may ultimately have to be united with it. 



3. Atheris ceratophorus. 



Atheris ceratophora, Werner, Verh. zool.-bot. Oes. Wien, xlv. 1895, 

 p. 194, pi. V. fig. 1. 



Rostral twice and a halt as broad as deep ; head-scales strongly 

 keeled, 9 or 10 across the interorbital region ; three erect, horn-like, 

 supraciliary scales, the longest as long as the eye ; 16 or 17 scales 

 round the eye ; two series of scales between the eye and the labials ; 

 nostril between two nasals ; 10 or 11 upper labials ; a pair of chin- 

 shields in contact with four lower labials on each side ; gular scales 

 keeled. Scales strongly keeled, in 25 rows. Ventrals 142 ; anal 

 entire ; subcaudals 55. Dark olive above, with black spots forming 

 more or less regular cross-bands ; pale olive beneath, speckled with 

 black. 



Total length 210 millim. ; tail 65. 



East Africa. 



a. $ (V. 142 ; C. 56). Usambara. Dr. F. "Werner. (Type.) 



9. ATEACTASPIS. 



Atractaspis, Smith, Bl. Zool. S. Afr., Rept. (1849) ; Dum. ^ Bibr. 



Erp. Gin. vii. p. 1303 (1854) ; Giinth. Cat. Col. Sn. p. 239 (1858) ; 



Jan, Hev. Sr Mag. Zool. 1858, p. 518 ; Cope, Proc. Ac. Philad. 



1859, p. 342; Peters, Eeise n. Mossamb. ill. p. 141 (1882). 

 Brachycranion, Sallow. Proc. Ac. Philad. 1854, p. 99 ; Cope, I. c. 

 Eurystephus, Cope, Proc. Ac. Philad. 1862, p. 337. 

 Clothelaps, Cope, Trans. Amer. Philos. Soc. zviii. 1895, p. 211. 



Poison-fangs enormously developed ; a few teeth on the palatines, 

 none on the pterygoids ; mandible edentulous in front, with two or 

 three very small teeth in the middle of the dentary bone. Head 

 small, not distinct from neck, covered with large symmetrical 

 shields ; nostril between two nasals ; no loreal ; eye minute, with 

 round pupil. Postfrontal bone absent. Body cyhndrical; scales 

 smooth, without pits, in 17 to 37 rows ; ventrals rounded. Tail 

 short ; subcaudals single or in two rows. 



Tropical and South Africa. 



This genus is remarkable as presenting the most extreme speciali- 

 zation in the Viperine direction, the poison-fangs being as large in 

 proportion as in any other form and the solid teeth on the palate 

 and mandible, which are much reduced in number in many of the 

 Crotalines, having almost disappeared. 



