238 



REPTILES OF THE WORLD 



delve into the intricacies of the more difficult genera, 

 as the rows of scales round the body, the arrangement 

 of the head plates, and the number of the abdominal and 

 subcaudal plates are characters of great value. The 

 coloration of a specimen and its locality are also impor- 

 tant factors to the student taking up the subject in a 

 general way. 



Following is a bird's-eye view of the classification of 

 the Colubridce: — 



SERIES A. Aglypha. All the teeth solid — no grooved or perforated 

 fangs. Harmless Snakes. 



Subfamily I. Acrochordince. Five genera. River Snakes of S. E. 

 Asia; 1 in Central America. The scales are not 

 overlapping as with most serpents. 



Subfamily II. Colubrinw. One hundred and seventeen genera. The 

 typical harmless snakes. The scales are overlap- 

 ping. Every graduation of form from extremely 

 slender to very stout is represented. All parts of 

 the world where snakes are found. 



Subfamily III. Rhachiodontince. A single genus with one species. A 

 few teeth in the upper and lower jaw — an egg- 

 eating snake. Tropical and South Africa. 

 SERIES B. Opisthogli/pha. One or more pairs of grooved venom-con- 

 ducting fangs in rear of the upper jaw. While they 

 are able to quickly benumb their prey, most of these 

 snakes are but mildly poisonous to man. 



Subfamily I. Homalopsince. Ten genera. Strictly aquatic. Found 

 commonly in rivers and harbors of the East Indies, 

 Papuasia and North Australia. 



Subfamily II. Dipsadomorphince. Sixty-nine genera. The majority 

 of the species rather elongate or exceedingly slender. 

 Arboreal, terrestrial, burrowing and semi-aquatic. 

 Found in all parts of the world but northern por- 

 tions of the Northern Hemisphere. 



Subfamily III. Elachistodontince. A single genus and one species 

 found in Bengal. In relation to the Opisthoglypha 

 the genus occupies a similar position as Dasypeltis 

 (Rhachiodontinw) to the Aglypha. 

 SERIES C. Proteroglypha. A pair of short, rigidly attached, caniculated 

 fangs in the forward part of the upper jaw. Some 

 of the most deadly known snakes are provided with 

 this dentition. 



Subfamily I. Hydrophiinw. Ten genera. The Sea Snakes — strictly 



