200 



YERTEBRATA. 



ANGIOSTOMATA. Mouth not dilatable. Teeth variable, but no 

 poison-fangs. With anal spurs. 



As in Opoterodontia, with which this suborder is sometimes 

 combined, the mastoid, when present, is united with the temporal 

 bone, and the os quadratum is fixed. The anal spurs are the 

 condensed epidermis of the rudimentary hind limbs. 



Cylindrophida. 

 Hysia = Tortrix. 

 Cylindrophis. 



Uropeltidce. 

 Uropeltis. 



AGLYPHODONTIA ( Colubrina = Colubriformia). Mouth dila- 

 table. Solid hooked teeth in both jaws. No poison-fangs. 



Innocuous; a few have fangs, but no poison-glands. Rudi- 

 ments of a pelvis and hind limbs are found in some of the Boidse. 

 Tail prehensile in many species. 



CalamariidcB. 

 Calamaria. 

 Oligodon. 



Colubrida. 

 Coronella. 

 Ablates. 



Simotes. 

 Tachyinenis. 

 Liophis. 

 Natrix Tropido- 



notus (Snake). 

 Coluber. 

 Zamenis. 

 Dromicus. 

 Herpetodryas. 



Bhachiodontidee. 

 Rhachiodon. 



Homalopsidce. 

 Hy drops. 

 Herpeton. 

 Homalopsis. 



Dryophidce. 

 Dryophis. 



Ccelopeltis. 



Dendrophidce. 

 Chrysopelea. 

 Dendrophis. 



Leptodira. 



Scytalida. 

 Scytale. 



Lycodontida. 

 Lycodon. 



Boid<B. 

 Eryx. 



Eunectes (Anaconda). 



Enygrus. 



Boa. 



Python. 



Liasis. 



Morelia. 



*Palseophis. 



Acrochordida. 

 Acrochordus. 



PROTEROGLYPHA. Mouth dilatable. Fangs in the upper jaw 

 grooved, with strong hooked teeth behind them. Poison-glands 

 always present. 



Palate and pterygoid bones with teeth, as well as the lower 

 jaw. The tail is vertically compressed in Hydrophidae. 



