3. SILTBUEA. 145 



B. Tail with, a flat disk of strongly keeled scales; 203-230 

 ventrals ; diameter of body 34 to 40 times in total length. 



11. hrougJiami, p. 152. 

 II. 17 scales round the middle of the body. 



A. Rostral entirely separating the nasals. 



141-166 ventrals ; diameter of body 22 to 



31 times in total length ; eye not half 



length of ocular 1. melanogaster, p. 146 . 



161-180 ventrals ; diameter of body 30 



to 38 times in total length ; eye half 



length of ocular 2. pvJmeyensis, p. 147. 



B. Nasals in contact behind the rostral. 



1. Eye not half the length of the ocular shield. 



a. Portion of rostral seen from above as long as its distance 



from the frontal, or shorter ; snout obtuse. 

 a. Tail round or slightly compressed ; upper caudal scales 

 distinctly keeled ; terminal scute without distinct 

 points ; 151-180 ventrals ; diameter of body 25 to 33 

 times in the total length . 4. petersii, p. 148. 

 /3. Tail round or slightly compressed ; upper caudal scales 

 smooth or faintly keeled ; terminal scute very small 

 and bicuspid. 

 152-173 ventrals ; diameter of body 27 



to 40 times in total length 5. maculata, p. 149. 



174-188 ventrals ; diameter of body 32 



to 38 times in total length 6. liura, p. 149. 



■y. Tail with a flat disk of strongly keeled scales ; 165- 

 172 ventrals; diameter of body 30 to 33 times in total 

 length 16. ruhroUneata, p. 155. 



b. Portion of rostral visible from above longer than its distance 



from the frontal ; upper caudal scales strongly keeled. 



a. Eostral not more than one third the length of the shielded 

 part of head. 

 193-234 ventrals ; diameter of body 30 



to 46 times in total length ; eye hardly 



one third length of ocular 7. ocellata, p. 150. 



184-195 ventrals ; diameter of body 30 



to 35 times in total length ; eye more 



than one third length of ocular .... 9. nitida, p. 151. 

 14.4—172 ventrals ; diameter of body 25 



to 32 times in total length 14. ellioti, p. 154. 



j3. Eostral compressed, keeled above, at least two fifths the 

 length of the shielded part of head ; snout acutely pointed. 

 156-168 ventrals ; diameter of body 26 

 to 32 times in total length; caudal 



disk quite flat 10. dir{digalerms,T^,\b2. 



VOL. I. L 



