XIII AGLYPHA ACROCHORDINAE COLUBRINAE 607 



of North-Eastern India ; another, Kothopsis, lives far from its 

 supposed allies, on the Isthmus of Darien, Central America. 



Acrochordus javanicus has no ventral shields. The head is 

 flat, covered with small granules, with the eyes and nostrils on 

 the upper surface. The general colour is dull olive - brown, 

 lighter and spotted beneath. The food consists of fishes. Total 

 length up to 4 feet. 



Chersydrus granulatus ranges from the coast of Madras to 

 New Guinea. The body and tail are compressed, and form a 

 ventral fold, covered with tiny scales like the rest of the body. 

 General colour grey above, yellow below. 



Sub-Fam. 2. Colubrinae. — The postfrontal bones are restricted 

 to the posterior border of the orbits. The maxillary and 

 dentary bones carry teeth on their whole length. The scales 

 are usually imbricating. This sub-family contains the over- 

 whelming majority of snakes, about 1000 species, all of them 

 harmless so far as poison is concerned. None of them reach a 

 great size, species of 6 or 7 feet in length being rare, e.g. 

 Zamenis mucosus, but a few species of the Indian genus Zaocys 

 s. Coryiiliodon grow to 10 feet. Most of the Colubrine snakes are 

 oviparous, but some, e.g. Coronella, are viviparous. Some are 

 aquatic, or semi-aqiiatic, others are absolutely arboreal, others 

 again prefer dry, sandy, or rocky localities, according to their 

 food. The distribution of the sub-family is cosmopolitan, finding 

 its natural limits only in the permanently frozen under-ground, 

 a condition which makes hibernation impossible. Most of them 

 love warmth and like to bask, although many are not fond of the 

 Ijroiling sun. In the temperate regions they hibernate. As a rule 

 they are intelligent and some of them become even affectionate. 



Tnypidonoius. — The teeth form closely set series on the whole 

 length of the maxillaries, palatines, pterygoids, and the greater 

 portion of the dentaries. The premaxilla is toothless. The 

 teeth of the maxillaries gradually increase in length, the posterior 

 teeth being the longest. The pupil is round. There is a pair 

 of internasal shields. The scales covering the body have each 

 an apical, sensory pit, are mostly keeled, and are arranged in 

 longitudinal series. The ventral shields are broad ; tlie sub- 

 caudals form two rows. This genus, with more than seventy 

 species, has a wide range, practically over the whole world with 

 the exception of New Zealand and the southern half of Australia,. 



