44 REPTILES AND BIRDS. 



and Fresh-water Colubrines (Natricinai) ; and he remarks that " they 

 are found in every part of the temperate and tropical regions, but 

 are only scantily represented in Australia and in the islands of the 

 Pacific. The species are so numerous, and show such a gradual 

 passage between extreme forms, that, although genera can be easily 

 characterised, it is almost impossible to distinguish wider groups by 

 definite characters." Among them the Coronellince approximate to the 

 immediately preceding families, and, like them, live on the ground, 

 and are not generally of brilliant colouring, though a few species 

 which frequent grassy plains are of a bright green colour. The 

 ColubrincR "form, as it were," writes Dr. Giinther, "the nucleus 

 of the whole sub-order of innocuous Snakes ; they are typical forms, 

 not characterised by the excessive development of some particular 

 organ, but by the fairness of the proportions of all parts. Yet some 

 of them have a more slender body than others which always live on 

 the ground ; they are land Snakes, but swim well when driven into 

 the water, or climb when in search of food. They are of moderate 

 or rather large size." In the Dryadiim the form is elongate and 

 somewhat compressed, indicating their climbing propensities ; they 

 have the body not so excessively slender as in the true Tree 

 Snakes, to which they lead off. They are much more numerous in 

 the New World than in the Old, and their ground-colour is very 

 commonly green. The Natricina are generally not very elongate or 

 compressed, and most of them have keeled scales. They freely enter 

 the water in pursuit of their food, which consists chiefly of frogs and 

 fishes. All the Snakes of the preceding three sub-families overpower 

 their prey by throwing some coils of the body round it, and commence 

 to swallow the victim after it has been smothered. The Natricina 

 swallow their prey immediately after they have seized it. 



Of the sub-family Corondlina, one species of the typical genus 

 Coronella is widely diffused over Europe, and has only of late years 

 been recognised as an inhabitant of the British Islands, the Coronella 

 austriaca. Another, C. girondica, occurs in Italy. Others are found 

 in Africa, America, and Australia. The C. austriaca has somewhat 

 the appearance of the Common Adder, for which it is often mistaken ; 

 but it is non-venomous, though rather fierce, biting and holding on 

 to whatever is placed in its way. As it occurs in Malta (where no 

 venomous species is known to exist), it is doubtless the Viper which 

 seized the apostle Paul. Several other genera are recognised. 



Of the Colubriim Rhinechis sca/an's, Coluber asculapii, C. quad- 

 rilineatus, Elaphis quater-radiatus, and three species of Zamenis 

 inhabit Europe ; in North America there are to be found five species 



