The Reptilia are divided into the Orders of =Crocodilia= (Crocodiles), =Chelonia= (Turtles and Tortoises), =Lacertilia= (Lizards), =Ophidia= (Snakes). [Illustration: FIG. 47.—The Adder (_Pelias berus_). ] Our native reptiles have no agricultural importance. I will, however, briefly mention the =Adder= (_Pelias berus_, Fig. 47), as it is dangerous to man. Head broad; tail much smaller than the hinder end of the body. Colour greenish grey or brownish. A black zigzag band runs along the dorsal side of the body. Length about twenty inches. The two hook-shaped poison-fangs are found in the front of the upper jaw; opening the mouth widely causes them to be erected. They are traversed by poison-canals through which the poison flows immediately into the two bloodless wounds. The adder lives in woods and on mountain slopes, where it devours mice. The poison has a decomposing action on the blood; it causes fever, and swelling of the part bitten, as well as sometimes of the neighbouring parts. The bite may be fatal. Alcohol is spoken of very highly as a remedy. [Illustration: FIG. 48.—The Grass Snake (_Tropidonotus natrix_). ] [Illustration: FIG. 49.—Blindworm (_Anguis fragilis_). ] The native =Ringed Snake= (_Tropidonotus natrix_, Fig. 48), three feet long, is bluish with belly flecked with black and white; a yellow and a black band on the neck. It is fond of going into the water, and eats frogs, newts, and insects. The =Smooth Snake= (_Coronella lævis_), two feet long, is brown, with black patches on the back, which, however, do not form a continuous band. Head dark velvety black. Devours lizards and blindworms. The =Blindworm= (_Anguis fragilis_) is indeed snake-like, or rather worm-like (Fig. 49), but nevertheless belongs to the lizards, with which its internal structure agrees. CLASS IV.: =AMPHIBIA= (AMPHIBIANS). [Illustration: FIG. 50.—Great Crested Newt (_Triton cristatus_); male above, female below. ]