258 UBOPELTIDJE. 



Synopsis of the Species. 



A. 19 scales round middle of body. 



a. Upper surface of tail convex. 



a'. 198-218 ventrals; diameter of body 30 



to 40 times in total length S. yrandis, p. 261. 



b'. 163-178 ventrals ; diameter of body 23 



to 30 times in total length S. nit/ra, p. 263. 



b. Tail with a flat disk of strongly keeled 



scales ; 203-230 ventrals ; diameter of 



body 34 to 40 times in total length .... S. brouyhami, p. 264. 



B. 17 scales round middle of body. 



. liostral entirely separating nasals. 



'. 141-106 ventrals; diameter of body 22 

 to 31 times in total length ; eye not 



half length of ocular S. melanogaster, p. 260. 



b'. 170-180 ventrals ; diameter of body 30 

 to 38 times in total length ; eye half 



length of ocular S. piilneyensis, p. 260. 



b. Nasals in contact behind the rostral. 

 a'. Eye not half length of ocular shield. 

 a". Portion of rostral seen from above 

 as long as its distance from frontal, 

 or shorter ; snout obtuse, 

 a. Tail round or slightly compressed ; 

 upper caudal scales distinctly 

 keeled ; terminal scute without 

 distinct points ; 151-180 ven- 

 trals ; diameter of body 25 to 33 



times in the total length S. peter sii, p. 261. 



ft. Tail round or slightly compressed ; 



upper caudal scales smooth or 



faintly keeled ; terminal scute 



very small and bicuspid. 



a. 154-165 ventrals ; diameter of 



body 27 to 35 times in total 



length S. maculata, p. 261. 



'. 174-188 ventrals ; diameter of 

 body 32 to 38 times in total 



length S. liura,:?. 262. 



y. Tail with a flat disk of strongly 

 keeled scales ; 165-172 ventrals ; 

 diameter of body 30 to 33 times 



in total length S. rubrolineata, p. 266. 



b". Portion of rostral visible from above 

 longer than its distance from fron- 

 tal ; upper caudal scales strongly 

 keeled. 



a. Rostral not more than one third 

 the length of shielded part of 

 head. 



a'. 193-234 ventrals ; diameter of 

 body 30 to 46 times in total 

 length; eye hardly one third 



length of ocular S. ocellata, p. 262. 



/3'. 184-195 ventrals ; diameter of 



