224 Zoologica: N. Y. Zoological Society [I; H 



the eggs of birds, sometimes of reptiles, upon which the serpent ap- 

 pears to wholly feed. After the covering of an egg is broken the 

 contents are permitted to flow down the serpent's throat, and the 

 fragments of shell afterwards disgorged. This snake appears to be 

 quite unique among members of the entire order in subsisting entirely 

 upon eggs; also in its habit of voluntarily disgorging useless remnants 

 of its food. 



The Opisthoglypha: The serpents of this division appear to 

 represent the early types of poisonous snakes. Specialization has 

 progressed to a point where venom-injecting teeth are evident, though 

 of a crude type. Their furrowed fangs are of invaluable assistance in 

 subduing the prey and are manipulated with great ingenuity. Owing 

 to the fangs being situated posteriorly, these snakes are unable to 

 strike and thus wound the prey, which is always tenaciously gripped 

 with imbedded fangs and held until it is overcome by the poison. 

 With the different method of feeding, there is a difference in the 

 food as compared with other poisonous Colubrines— the Proteroglypha. 

 The great majority of the Opisthoglypha feed upon cold-blooded 

 creatures, reptiles, amphibians, fishes and various invertebrates. 

 This is necessarily the case with a great number of species, owing to 

 the very short fangs which would be unable to pierce the pelage or 

 feathers of small mammels or birds, or efficiently inject the poison. 

 The simple fang mechanism of these serpents is primarily intended to 

 be employed in the subjugation of creatures with comparatively 

 naked skins, under which head must be included a favorite food 

 of many of the terrestrial and aboreal species — the lizards — the 

 scales of which are readily pierced by the strong, sharp fangs. With 

 some genera, like the South American Tomodon, the fangs are greatly 

 elongated and advanced to a position nearly under the eyes. This 

 dentition would be effective upon small birds and mammals, but 

 unfortunately, the writer has been unable to obtain examples for 

 observation. 



The Homalopsinae: This subfamily of the Opisthoglypha has 

 become specialized in assuming strictly aquatic habits and is thus 

 analagous to the Hydrophiinae of the Proteroglypha although the 

 members of the latter evince the more extreme specialization along 

 these habits in taking to the sea. With this specialization of habits 

 comes the necessary and characteristic diet of fishes. The members 

 of the Homalopsinae feed also upon batrachians, although fishes form 

 the greater part of their diet. Fishes with the fins terminating in 



