446 



THE SNAKES OF SOUTH AFRICA. 



Rostral moderate ; nostril in a single, semidividcd nasal 

 Rostral moderate ; nostril between two nasals and the 



intcrnasal ; maxillary teeth subequal 

 Rostral large, projecting, snout pointed . . 

 Rostral moderate ; nostril between the nasals ; one or 

 two middle maxillary teeth much enlarged 



/3. Scales keeled, in lo or 21 rows ; eye 

 very large . . 

 c. Pupil horizontal ; eye large ; scales in 

 19 rows ; body very slender . . 

 B. Eye small or verj' small ; head not distinct from 

 neck. 



1. Sub-caudals in pairs ; no praeocular. 

 Scales in 1 5 rows ; no internasals 



Scales in 17 or 19 rows ; internasals present 



2. Sub-caudals single. 

 Scales in 23 to 27 rows ; no praeocular 



Scales in 15 rows ; nasal in contact with a praeocular . . 

 III. Protcroglypha, with grooved fangs at the anterior 

 end of the upper jaw. — Poisonous. 



A. Tail compressed, oar-shaped ; head narrow and 



elongate ; no distinctly enlarged ventrals (Sea- 

 snakes) 



B. Tail cylindrical, ending in a point. 



1. Head short. 



a. Scales in 17 rows or more ; internasal 



bordering the nostril. 

 Rostral moderate ; scales smooth 

 Rostral moderate ; scales strongly keeled 

 Rostral very large, detached on the sides ; scales smooth 

 or keeled on posterior part of body . . 



b. Scales in 13 or 15 rows. 



Nostril between two nasals ; scales in 13 rows ; eye 



small 

 Nostril in a single nasal ; scales in 15 rows ; eye very 



small 



2. Head narrow, elongate ; scales very oblique, 



in 19 to 23 rows ; body slender 



A mplorhintis. 



Trimerorhinus. 

 Rhamphiophis. 



Psammophis. 



Dispholidus. 



Thelotornis. 



Amblyodipsas. 

 Calatnelaps. 



Macrelaps. 

 A parallactus. 



Hydrus 



Naia. 

 Sepedon. 



Aspidelaps. 



Elapechis. 



Homorelaps. 



Dendraspis. 



A.—AGLYPH.E. 



I. TROPIDONOTUS. 



Kuhl, Bull. Sc. Nat. ii., 1824, p. 81 ; Bouleng. Cat. Sn. i. p. 192. 



Two Species in South Africa. 



Ventrals 162-180 ; anal entire . . . . . . . . T. IcBvissmus. 



Ventrals 1 31-149 ; anal divided . . . . . . . . T. olivaceus. 



I. TrOPIDONOTUS L^EVISSIMUS. 



Natrix Iccvissima, Giinth. Ann. & Mag. N. H. (3) ix., 1862, p. 124, 



pi. ix. fig. 4. 

 Tropidonotus lavissimus, Bouleng., i.e., p. 226. 

 Grayia hibrica, W. Sclater, Ann. S. Afr. Mus. i., 1898, p. 109, pi. V, 



fig. I. 

 Cape Colony, Natal. 

 Tsomo, Transkei District. — Type of Grayia lubrica. 



