african snakes. 209 



22. Scaphiophis. 



Peters, Mon. Berl. Ac. 1870, p. 644; Bouleng. Cat. Sn. ii. 

 p. 254. 



1. Scaphiophis albopunctatus Peters, t. c. p. 645, pi. i. fig. 4 ; 

 Bouleng. 1. c. ; Bocage, Herp. Aug. p. 102. 



Tropical Africa, from the Soudan to the Congo. 



23. Dasypeltis. 



Wagl. Syst. Am ph. p. 178 ; Bouleng. Cat. Sn. ii. p. 353. 



1 . Dasypeltis scabra. 



Coluber scaler Linn. Mus. Ad. Fricl. p. 36, pi. x. fig. 1. 

 Dasypeltis scabra Bouleng. t. c. p. 354 ; Bocage, Herp. Ang. 

 p. 106. 



Tropical and South Africa, Egypt, South Arabia. 



B. Opisthoglypha. 



— l I. Eye moderate or large; head more or less distinct from neck ; loreal present ; 

 no upper labials in contact with the parietal. 

 J A. Pupil vertically elliptic; head short, very distinct from neck. 



1. Subcaudals in two rows. 



Vertebral scales not enlarged ; scales in 19 rows ; two super- 

 posed anterior temporals Tarbophis. 



Vertebral scales not enlarged ; scales in 17 or 19 rows ; a 



single anterior temporal Leptodira. 



Vertebral scales enlarged : scales in 19 to 25 rows Dipsadomorphus. 



2. Subcaudals single ; scales in 17 rows Dipsadoloa. 



B. Pupil round. 



1. Loreal not more than once and a half as long as deep ; scales in 17 rows, 



not oblique. 



Nostril in a semidivided nasal; anal entire , AmplorJiinus. 



Nostril between two nasals and the internasal ; scales more or 



less distinctly concave ; anal divided Trimerorhinus. 



Nostril between the nasals ; snout acutely pointed or curved 



in profile ; rostral large, hollowed ont beneath BhampMophis. 



2. Loreal at least once and a half as long as deep; scales more or less 



oblique. 



A single anterior temporal ; scales in 17 rows Dromophis. 



Usually two superposed anterior temporals ; scales in 11 to 



17 rows ; one or two middle maxillary teeth much enlarged. Psammophis. 



3. Loreal not more than once and a half as long as 



deep ; nostril in an undivided nasal ; scales very 

 narrow, oblique, more or less strongly keeled, in 

 19 or 21 rows Displwlidus. 



C. Pupil horizontal; nostril in an undivided nasal; 



scales narrow, oblique, feebly keeled, in 19 rows Thelotomis. 



