( xxi ) 



Family TORTRIClDiE. 

 Ventral scales slightly enlarged. A mental groove. Upper 

 labials four. 



Cylindrophis. 



Nostril in a large undivided nasal. Eye small. Pupil round. 

 Width of interocular space longer than the 



snout ... C. rufus. 



Width of interocular space equal to that of 



the snout ... C. maculatus. 



Family UROPELTID^. 



Tail truncated, short. Terminating in a rough disk or covered 

 with keeled scales. 



Rhinophis. 



Nasals separated by the rostral 



Rostral keeled above. Brownish . . . R, oxyrhynchus. 



Rostral keeled above. Yellowish, black 



dotted ... R. punctatus. 



Rostral much less than half the length of 



the head . . . R. -planiceps. 



A row of triangular white spots along the 



sides ... R. Trevelyanus. 



Belly and sides red, with black spots ... R. sanguineus. 

 Caudal very small, snout pointed ... R. Bly thii. 



Caudal very small, snout obtuse . . . R. Pulneyensis. 



Caudal small, bicuspid ... R. grandis. 



Uropeltis. 



Tail terminating in a flat rough scaleless shield. 

 Tail obliquely truncated, disk scabrous ... U. grandis. 



SiLYBURA. 



The supraorbital and postocular united. 



Terminal scale of tail horizontal. 

 Disk flat, scales on it, 1 — 2 keeled ... S. macrolepis. 



