snakes of west africa. 297 



5. Atheris. 



Cope, Proc. Ac. Philad. 1862, p. 337; Bouleng. Cat. Sn. iii. 

 p. 508. 



fSi/nopsis of tke Species. 



9-11 scales across liead, from ej-e to eye, 15-17 round eye; 25-36 



scales across body -4. clilorecMs. 



7-9 scale* across head, from eye to eye, 10-16 round eye ; 15-25 



scales across body \ -^- squamigei: 



8-10 scales across bead, from eye to eye, 16-17 round eye ; 25 



scales across body ; several erect, horn-like superciliary scales. A. ceratophoriis^ 



1. Atheris chlorechis. 



Vipera cMoroechis Schleg. Versl. Ak. Amsterd. iii, 1855, p. 317. 

 Athei'is chlorechis Bouleng. 1. c. 

 Liberia to Gaboon. 



2. Atheris squamiger. 



Echis squamigera Hallow. Proc. Ac. Philad. 1854, p. 193. 



Atheris squamiger Bouleng. t. c. p. 509. 



Calabar to Angola, eastwards to Uganda and the Itnri. 



3. Atheris ceratophorus Werner, Yerh. zool.-bot. Ges. Wien,. 

 xlv. 1895, p. 194, pi. V. fig. 1 ; Bouleng. t. c. p. 510. 



Togoland, East Africa. 



6. Atractaspts. 

 A. Smith, 111. Zool. S. Afr., Kept. ; Bouleng. Cat. Sn. iii. p. 5ip. 



Si/nopsis of the Species. 



I. Anal divided ; all or most of the subcaudals paired. 



2iid lower labial separated from its fellow by the chin-shields ; 



scales ill 23-27 rows; ventrals 217-257 A. irregularis. 



2nd lower labial forming a suture with its fellow ; scales in 19-21 



rows; ventrals 30^^-331 A. reticulata. 



2nd lower labial forming a suture with its fellow ; scales in 21-23 



rows; ventrals 386-359 A. heteroeliilus^ 



II. Anal entire; all or most of the subcaudals paired. 



Scales in 21 rows; ventrals 198-222 .• A. matscliiensis.. 



Scales in 29 rows; ventrals 226 A. caudalis. 



III. Anal entire ; all or most of the subcaudals single. 



A. Postocular in contact with a large temporal. 



1. Snout rounded, feebly projecting. 



2nd lower labial very large, forming a suture with its fellow; 



scales in 23-27 rows; ventrals 178-193 A. corpulenta. 



3rd lower labial longest ; scales in 21 rows ; ventrals 195 A. houlenqeri. 



3rd lower labial longest; scales in 19-21 rows; ventrals 251-300 A. aterrima. 



2. Snout cuneiform; scales in 31 rows; ventrals 210 A. dahomej/ensis^ 



B. Temporals small, 2 or 3 superposed in front. 



Snout cuneiform ; upper part of rostral as long as its distance from 



the frontal; scales in 25 rows ; ventrals 210-223 A. microplwlis. 



Snout rounded, upper part of rostral much shorter than its dis- 

 tance from the frontal ; scales in 25-29 rows ; ventrals 214- 

 225 A. tvatsonii. 



