LIST OF SOUTH AFRICAN SNAKES. 



445 



Family COLUBRID^. 

 Synopsis of the South African Genera. 



I. Aglyphce, without grooved fangs in the upper jaw. — 



Harmless. 



A. Scales smooth, in 19 rows or more. 



1. Pupil round ; posterior maxillary teeth longest. 

 Scales in 19 rows ; internasal not entering the nostril ; 



snout rounded . . . . . . . . . . . . Tropidonotus. 



Scales in 27 to 31 rows ; internasal entering the nostril ; 



snout with vertical sides, more or less prominent . . Pseudaspis. 



2. Pupil vertically elliptic or subelUptic ; anal 



entire. 



Scales in 19 rows ; frontal at least once and a half as 



long as broad ; maxillary teeth equal . . . . Ablabophis. 



Scales in 19 to 23 rows ; frontal broad and short ; pos- 

 terior maxillary teeth shortest . . . . . . Lamprophis. 



Scales in 23 to 33 rows, with apical pits ; anterior 



maxillary teeth strongly enlarged . . . . . . Boodon. 



B. Scales smooth, in 15 or 17 rows. 



1. Tail short (sub-caudals not more than 50 pairs). 

 Pupil vertically elliptic ; rostral small ; anterior maxil- 

 lary teeth longest . . . . . . . . . . Lycophidium. 



Pupil vertically elliptic ; rostral very large, with angular 

 horizontal edge ; posterior maxillary teeth strongly 

 enlarged . . . . . . . . . . . . Prosymna. 



Pupil round ; rostral small ; nasal single ; anterior 



maxillary teeth longest . . . . . . . . Homalosoma. 



2. Tail long (sub-caudals more than 80 pairs) ; 



pupil round ; posterior maxillary teeth 



longest. 

 Sub-caudals not keeled . . . . . . . . . . Chlorophis. 



Sub-caudals keeled and notched . . . . . . . . Philothamnns . 



C. Scales keeled ; pupil vertically elliptic. 



Scales in 15 to 17 rows, of vertebral row enlarged and 



bicarinate ; anterior maxillary teeth longest . . Simocephalus. 



Scales in 23 to 27 rows, laterals very oblique and with 



serrated keels ; teeth very small and few . . . . Dasypeltis. 



II. Opisthoglyphes , with grooved fangs at the posterior 



end of the upper jaw. — More or less poisonous. 

 A. Eye moderate or large ; head more or less distinct 

 from neck. 



1. Subcaudals single ; pupil vertically elliptic ; 



parietals broken up into small shields . . Pythonodipsas. 



2. Subcaudals in pairs. 



a. Pupil vertically elliptic ; scales in 17 or 



19 rows. 



Anal divided ; loreal separated from the eye by the prae- 

 ocular ; maxillary teeth decreasing in size pos- 

 teriorly . . . . . . . . . . . . . . Tarhophis 



Anal entire ; loreal separated from the eye by the prae- 

 ocular ; maxillary teeth increasing in size pos- 

 teriorly . . . . . . . . . . . . . . Leptodira. 



Anal entire ; loreal entering the eye . . . . . . Chamcstortus. 



b. Pupil round. 



a. Scales smooth (or feebly keeled on 

 the posterior part of the back) in 

 13 to 17 rows. 



