2 OPHIDIA. 
2, No vestiges of limbs ; supratemporal absent. 
, 5. Uropeltide, Vol. I. p. 137. 
B. Coronoid absent ; supratemporal present. 
1. Maxillary horizontal; pterygoid reaching quadrate or 
mandible. 
Prefrontal bone in contact with nasal. 
6. Xenopeltids, Vol. I. p. 167. 
Prefrontal not in contact with nasal. - 
7. Colubridez, Vol. I. p. 169. 
2. Maxillary horizontal, converging posteriorly towards 
palatine; pterygoid not reaching quadrate or mandible. 
8. Amblycephalide. 
3. Maxillary vertically erectile perpendicularly to ecto- 
pterygoid; pterygoid reaching quadrate or mandible. 
9. Viperide. - 
No serial arrangement can convey a correct idea of the affinities 
of the various groups as conceived by the classificator. A diagram 
is therefore appended illustrating the author’s views on the classifi- 
cation of the Ophidia, and, to a certain extent, their phylogeny. 
Leaving aside the Z'yphlopes and Glauconie, which should be 
regarded as degraded burrowing types independently derived from 
some Ophidian form less specialized than any with which we are at 
present acquainted, the family Boide, and more specially the Pythons, 
claim the position of ancestral group from which all other Ophidia 
may have been derived, in the manner illustrated by the diagram. 
This, if rightly conceived, shows how unnatural a classification 
into poisonous and harmless Snakes is. The Elapoids, for instance, 
long regarded as forming the passage from the Colubroids to the 
Vipers, stand apart, the author considering the Viperine maxillary 
as derived from the Opisthoglyphous type. 
9. Viperide. 7 
; | 8. Amblycephalide. 
5. Uropeltide. Ta. 0. Ee gh 7b. C. Proteroglypha. |. 2 > 
a 
a 
4. Ilysiide. 6. Xenopeltide. 7. Colubride (Aglypha). 
1. Typhlopide. 3. Boide. 2. Glauconiide. 
« 
