The Green and Yellow Snake is also about a yard in length, and is common in the south and west of France; they have been taken in the forest of Fontainebleau. The beautiful colours in which they are clothed causes them to be easily distinguished from the Viper. The eyes are edged with golden-coloured scales; the upper part of the body is of a very dark greenish colour, upon which is extended a large number of radiating lines, composed of small yellowish spots of different shapes, some long, others lozenge shape, giving it a chequered appearance. These chequers extend from the head to the tail. The belly is yellowish; the large plates which cover it have a black spot at each end, and are bordered with a very thin black line. This inoffensive reptile is extremely timid, and generally hides itself from observation, taking to flight at the least alarm. They are said to be easily tamed. [Illustration: Fig. 12.--_Tropidonotus viperinus._] The Viperine Snake (Fig. 12) has the body of a greyish or dirty yellow colour, having on the middle of the back a series of blackish spots so close to each other as to give the idea of one small continuous wavy line from head to tail. The sides are covered with isolated spots, forming lozenge-like figures, the centres of which are of a greenish tint. This is the smallest of all the European _Colubridæ_, and, like the others, it is found in most parts of Europe. [The _Psammophidæ_, or Desert Snakes, are akin both to the _Colubridæ_ and to the Tree Snakes of the next family; but the latter, remarks Dr. Günther, may always be distinguished either by their green coloration, by the horizontal pupil to the eye, or the absence of a long, anterior, maxillary tooth. In the _Psammophidæ_ the pupil of the eye is round or vertical. Most of the species of this family belong to the fauna of tropical Africa, which also produces a slender form (in _Psammophis elegans_). The other species are of a stouter habit, frequenting plains, or at all events living on the ground. Of the Indian _Psammophis condanarus_, Dr. Jerdon procured one which had killed and was swallowing a small Viper (_Echis carinata_), this being one of the few instances in which a non-Venemous Snake has been known to overpower a poisonous one. We have heard the same of a small Boa-like Serpent (_Chilabothrus?_) in the West Indies, which is said to prey upon the formidable _Crotalidæ_. The _Psammodynastes pulverulentus_ has a wide geographical range over South-eastern Asia and its islands. Although innocuous, it has the aspect of a Venemous species. In a kindred African family, the _Rachiodontidæ_, the species of _Dasypeltis_ have the maxillary teeth minute and few in number (four to seven); but they have also some remarkable gular teeth, which are formed by the elongated inferior spinous processes of the hinder cervical vertebræ. The object of the latter is to crush the shells of birds' eggs, upon which the Snakes in question habitually feed.