4 COLUBRID. 
t++t Internasals fused with the prefrontals, nasai 
fused with the first labial. 
87. Sympholis, I. p. 188. “ 
3. Posterior maxillary teeth strongly enlarged and sepa- 
rated from the rest by a very distinct interspace. 
* Scales with apical pits; snout rounded or obtusely 
conical. 
Scales forming longitudinal series; no suboculars. 
75. Liophis, II. p. 126. 0°" 
Scales forming longitudinal series ; 3 a series of suboculars. 
6. Cyclagras, II. p. 144. |. / 
Scales disposed obliquely ; no aie 
77. Xenodon, II. p. 144. /~ 
** Scales with apical pits; snout projecting, cunei- 
form. 
Scales smooth, in 19 or 21 rows. 
78. Lystrophis, Il. p. 151. §. 0! 
Scales keeled, in 23 to 27 rows. 79. Heterodon, II. p. 153. 
*** Scales without pits; snout obtuse ; head narrow. 
80. Aporophis, II. p. 157. < 
c. Longitudinal series of scales in odd numbers; ventrals 
with a suture-like lateral keel, and a notch on each 
side corresponding to the keel. 
a. Scales of vertebral row not enlarged. 
Scales smooth ; subcaudals keeled and notched like the ventrals. 
67.-Philothamnus, II. p. 98. 
Scales keeled; subcaudals keeled and notched like the ventrals. 
68.- Gastropyxis, II. p. 102. 
Scales keeled; subcaudals without keel or notch. 
69. Hapsidophrys, II. p. 103. 
B. Scales of vertebral at heel 
4, Dendrophis, II. p. 77. 
4, Palatine’ and pteryg ooid teeth absent or few ; ; maxillary bone 
short, with 5 to 8 teeth. 
a. Maxillary teeth forming an uninterrupted series, 
Pupil round; snout projecting, obtuse. 
93. ‘Oligodon, II. p. 233. 
Pupil vertically subelliptic ; snout with angular horizontal “ae 
94,°Prosymna, II. p. 246. « 
