snakes of east africa. 639 



4. Atheris. 



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

 p. 508. 



Synopsis of the Species. 



No Lorn-like superciliiiry scales ; scales in 15 to 25 rows ; gular 



scales strongly keeled A. squamiger. 



No horn-like superciliary scales ; scales in 25 to 32 rows ; gular 



scales smootli or very feebly keeled A. nitsehei. 



Several erect, horn-like superciliary scales ; scales in 25 rows ... A. ceratophorws. 



1. Atheris squamiger. 



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



Atheris sqtiamiger Bouleng. t. c. p. 509. 



Uganda, Central Africa, "West Africa from Calabar to Angola. 



2. Atheris nitschei Tornier, Zool. Jahrb., Sjst. xv. 1902, 

 p. 589, fig. 



Atheris tvoosnami Bouleng. Ann. & Mag. N. H. (7) xviii. 1906, 

 p. 37, and Tr. Zool. Soc. xix. 1909, p. 246, pi. ix. 



N.W. and E. of Lake Tanganyika, and Mt. Ruwenzori. 



3. Atheris ceratophorus Werner, Yerli. Zool.-bot. Ges. 

 Wien, xlv. 1895, p. 194, pi. v. fig. 1 ; Bouleng. Cat. Sn. iii. 

 p. 510. 



German East Africa and Togoland. 



5. Atractaspis. 



A. Smith, III." Zool. S. Afr., Rept. ; Bouleng. Cat. Sn. iii. 

 p. 510. 



Synopsis of the Species. 



I. Aual divided ; all or most of the subcaudals i)aired ; scales in 23 to 27 rows. 



Snout rounded ; one postocular; third lower labial largest A. irregularis. 



Snout pointed; one postocular; third lower labial largest A. conrad.ii. 



Snout rounded; two postoculars ; fourth or .fifth lower labial 



largest A. bvpostocularis. 



II. Anal entii'e ; all or most of the subcaudals single. 



A. Postocular in contact with a large temporal. 



Snout cuneiform ; first lower labial in contact with its fellow 

 behind the symphysial ; scales in 23 rows ; ventrals 227- 

 248 A. rostrata. 



Snout rounded ; first lower labial in contact with its fellow 

 behind the symphysial ; scales in 19 or 21 rows ; ventrals 

 251-300 A. aterrima. 



Snout rounded; symphysial in contact with the chin-shields; 



scales in 25 rows ; ventrals 242 A. Tcatangce. 



B. Temporals small, 2 or 3 superposed in front; snout sub- 



cuneiform ; scales in 29 to 37 rows ; ventrals 212-245. A. microlepidota. 



44* 



