This is the scientific name of a creature generally known under the title of the horned-toad, though really a lizard. Its head is of a light brown, marked with dark spots, the under part being of a dull yellow; and is armed with long conical spines, set round the edge and pointing backwards. The back is covered with shorter and stouter spines, of a triangular shape, extending to the very point of the tail-- also armed with a strong row of spines, which gives it a completely toothed appearance. The colour of this curiously covered back is grey, with irregular bands of chestnut-brown across it. Formidable as it looks, it is not only harmless, but never retaliates when attacked, and remains perfectly quiet when taken in the hand. It is also easily tamed, and learns to know its owner, and to take food from his hand--preferring little red ants, though it eats readily beetles, flies, and other insects. From its small, rounded form, and the mode of sitting, it has in all likelihood gained its common name of the horned-toad. SNAKES:--THE RATTLESNAKE. Throughout North America there are no small number and variety of venomous snakes. The rattlesnakes are perhaps the most numerous, frequenting all parts of the country, though they generally keep to the uninhabited portions. They are found on the northern shores of Lake Superior--though the ground is covered for several months in the year with snow--and often appear in the regions to the west, in the same latitude, up to the Rocky Mountains. They would render some districts uninhabitable, were it not for the signal-giving rattles with which they are armed. Even quadrupeds are alarmed at the sound, and endeavour to make their escape from them; and horses, it is said, lately arrived from Europe, show the same dread of these deadly serpents as do those born in the country, so that nothing will induce them to pass within striking distance of the creatures. The wanderer through the forest starts back with dismay as he comes suddenly upon one of these venomous reptiles, and hears its ominous rattle when too near to escape. He must muster all his nerve, and strike it with his stick as it springs; for a wound from its fangs will, as he knows, bring certain death, far-away from human aid. The rattlesnake, like others of its tribe in cold regions, hibernates in winter; and as the autumn comes on, seeks some convenient crevice in which to pass the cold season--generally in the neighbourhood of marshy ground, where it can cover itself up in the masses of a peculiar species of moss growing in such situations. The reptiles are here, during the winter, frequently hunted out and destroyed. At that time, too, their bite is much less dangerous than in the summer--the amount of venom appearing to decrease with the increase of cold. THE BANDED AND MILITARY RATTLESNAKES.