DIVISION OPISTHOGLYPHA. 119 



eye minute, with round pupil ; nostril in a divided or semi- 

 divided nasal ; no loreal ; no preocular ; no anterior temporal. 

 Body cylindrical. Scales smooth, without pits, in 17 or 19 

 rows. Ventrals rounded. Tail very short, obtuse ; sub- 

 caudals in two rows. 



Genus Macrelaps. — Maxillary short, with 4 moderately large teeth, 

 followed by a very large grooved fang situated below the eye ; 

 anterior mandibular teeth enlarged, third to fifth longest. Head 

 small, not distinct from neck ; eye minute with round pupil ; 

 nasal divided ; no loreal ; no preocular ; prefrontal entering 

 the eye. Body cylindrical ; scales smooth, without pits, in 

 25 or 27 rows ; ventrals rounded. Tail short ; sub-caudals 

 single. 



Genus Aparallactus.— Maxillary short, with 6 to 9 small teeth, 

 followed by a large grooved fang situated below the eye ; 

 anterior mandibular teeth longest. Head small not distinct 

 from neck ; eye small, with round pupil ; nasal entire or divided, 

 no loreal. Body cylindrical ; scales smooth, without pits, in 

 15 rows; ventrals rounded. Tail moderate or short; sub- 

 caudals single. 



Genus PYTHONODIPSAS. 

 This Genus is represented by a single Species. 

 {For Scientific Description, see Synopsis of Genera of the DipsadomorphincB.) 



I. Pythonodipsas carinata. — Keeled Snake ; Driekant Slang. (Kiel 

 Slang.) 



Colour — Sand-coloured or pale buff above, with a double alternating 

 series of square grey spots, a few of which may coalesce to form 

 transverse bars ; lips with vertical grey bars ; lower parts 

 white. 



Average length — Two feet. 



Distribution — -Damaraland ; Zambesi Regions. 



Genus TARBOPHIS. 

 A single Species in South Africa. 

 KEY TO THE SPECIES. 

 Scales in 19 rows ; anal divided. Three labials 



entering the eye. Ventrals 206-242 . . Tarbophis semiannidatus. 

 I. Tarbophis semiannulatus. Tiger Snake; Tijger Slang. (Tier Slang.) 

 Synonyms — Telescopus semiannulatus. 



Colour — Yellowish or pale brown above, with 24 to 34 dark brown 

 or blackish transverse rhomboidal spots or cross-bars on the 

 body ; head without any spots or markings ; yellowish-white 

 beneath. 

 Average length — 2 feet 6 inches. 



Distribution — Natal ; Basutoland ; Orange Free State ; British Bechu- 

 analand ; Transvaal ; Delagoa Bay ; Portuguese East Africa ; 

 Central and East Africa. 



