C. Maxillary with only two large canaliculated fangs side by side, one of which may be missing; anterior mandibular teeth longest
Vipera, Ancistrodon.
Fig. 12—Maxillary and Mandible of—(a) Tarbophis fallax; (b) Cœlopeltis monspessulana; (c) Macroprotodon cucullatus. (From British Museum Catalogue of Snakes)
In counting the teeth for the purpose of using this key, care must be taken to ascertain the full number, as it frequently happens that one or more are missing; but their place is indicated by the shallow pits in which their base was implanted, the overlooking of which might convey the impression of a hiatus such as is characteristic of certain genera—Macroprotodon, for instance. Needless to say, the loose teeth which are in reserve on the inner side of the jaws or behind the tubular fangs are not taken into consideration, the numbers given being those of functional teeth only. Although as a rule the teeth can be counted easily, on a specimen preserved in spirit, by simply pushing aside the lips and gums with the finger, it is sometimes necessary to remove and clean the bones of the jaws, an operation which does not require much skill.