There are two or three species of whip snakes, or Dryadidae, remarkable for the slender elegance of their forms, and in general for the great beauty of their colouring, as well as for the rapidity of their movements. The whip snake, having seized its prey, winds its light and lithe body round its victim, coil upon coil, like the boa and anaconda, and strangles it in its embrace. The emerald whip snake (Philodryas viridissimus) is one of the most beautiful. So slender is its body that, although two feet long or more, it can coil itself up within a space not larger than the hollow of the hand. It lives in trees, and may be seen sporting amid the branches; but the moment it catches sight of a person, away it darts, scarcely moving the branches and leaves amid which it makes its way. THE GREEN SNAKE. Delicate in form, and of the brightest grass-green--while, like the rest of its family, perfectly harmless--the green snake is a great favourite with the Brazilians; and as it is easily tamed, young girls may often be seen carrying it about, winding it round their throats or wrists, forming it into living necklaces or bracelets. It lives in trees, among the green foliage, over which it rapidly glides in search of insects-- its usual food. FROGS AND TOADS. Frogs abound of all sizes, living in marshes, some on dry ground, and others inhabitants of trees--many with voices which resound loudly through the midnight air. Toads, too, are numerous, some of enormous size. They may be seen on bare, sandy places--huge fellows, seven inches in length and three in height--crawling over the ground, utterly indifferent to the appearance of a stranger among them. Among the frogs is the curious tingeing frog (Hylaplesia tinctoria), which is an inhabitant of the forest. It may be seen during the day crawling along the branches, but at night it takes up its abode under the loose bark. Except during the breeding season, it seldom visits the water. It then, like the rest of its species, goes there for the purpose of depositing its eggs. It is generally of a dark colour-- sometimes quite black--with a white spot on the head and two white lines running along each side. It gains its name from the use the Indians are said to make of it. They employ it as they do the parrot-fish, to give a different colour to the plumage of their parrots. To do this they pull out the feathers from the spots to which they wish to impart a new tint, and then rub the blood of the frog into the wounded skin. When the new feathers grow, they are said to be of a bright yellow or vermilion hue. The bi-coloured tree-frog (Phyllomedusa bicolour) is of considerable size, and is the only one of its family at present known. The upper part of the body is of the deepest azure-blue, while the under parts are of a pure white, sometimes of a rosy tinge. The thighs and sides are spotted with the same tinge as the abdomen.