154 COLFBEID^. 



the length of the snout ; suboaudals 



130-158 4. punetulatus, p. 159, 



Sixth upper labial as long as the eye, 

 which is half the length of the snout ; 

 suboaudals 132 5. trigrammus, p. 159, 



6. Four lower labials in contact with the anterior chin' 

 shields ; eight or nine upper labials ; ventrals 151-168 ; 

 subcaudals 100-108 6. suhtceniatus, p. 160. 



B. Eostral as deep as broad, well visible from above. 



1. Nineupperlabials, three entering the eye; ventrals 161-173; 



subcaudals 109-127 7. bocagii, p. 161. 



2. Eight upper labials, exceptionally seven or nine, two 



entering the eye. 



a. Frontal, in the middle, narrower than the supraocular ; 

 ventrals 155-198 ; subcaudals 90-116. 



Prseocular narrowly in contact with or 



separated from the frontal, which is as 



long as or longer than its distance from 



the end of the snout 8. sibilans, p. 161. 



Prseocular extensively in contact with the 



frontal ; snout short, forehead strongly 



grooved 9. furcatus, p. 164. 



Prseocular separated from the frontal , which 



is considerably shorter than its distance 



from the end of the snout 10. longifrons, p. 165. 



h. Frontal, in the middle, nearly as broad as the supraocular j 

 prseocular not reaching the frontal. 



Snout nearly twice as long as the eye ; 



ventrals 156-182 ; subcaudals 75-90 . . 11. eondanarus, p. 165, 

 Snout once and a half to once and two 



thirds as long as the eye ; ventrals 153- 



163 ; subcaudals 64-95 12. brevirostris, p. 166. 



C. Rostral a little broader than deep, scarcely visible from above; 



snout twice to twice and a half as long as the eye ; nine 

 upper labials, fifth and sixth entering the eye ; ventrals 179- 

 202 ; subcaudals 144-161 13. elegans, p. 167. 



II. Scales in 15 rows. 



Nine or ten upper labials (rarely eight) ; 



ventrals 142-164 ; subcaudals 100-131. 14. biseriatus, t^. 1Q8. 

 Eight upper labials (rarely seven) ; ventrals 



136-155 ; subcaudals 62-81 15. crucifer, p. 169. 



III. Scales in 13 rows ; ventrals 144 ; subcaudals 108. 



16. pulcher, p. 169. 



IV. Scales in 11 rows ; ventrals 141-155 ; subcaudals 57-81. 



17. angolensis, p. 170, 



