light, it assumes a darker tint, approaching olive brown; and the branchial tufts become deeper. The light, however, is evidently distressing, and the animals are glad to creep beneath the shelter of any substance which may serve as a protection from its influence. For some time after its first discovery, the Proteus was supposed to be the larva, or Tadpole of some unknown animal, inhabiting the deep subterranean cavities, and whose form it would finally assume, as the common Tadpole of our ponds becomes the Frog. This idea is now abandoned; its true character has been made out by observation and anatomical research, and its relative situation in the chain of animated beings ascertained: still, as it regards many points in its economy, we are yet in the dark.

On looking at the Proteus, and reflecting on its mysterious nature, on its dwelling, so apparently unsuited for the existence of such a being, on its adaptation to the circumstances in which it is placed, we cannot but trace the hand of God, who hath fixed for every thing the bounds of its habitation, and organized every thing so that it shall fulfil its allotted destiny.

GENUS MENOBRANCHUS.

The genus Menobranchus, of Harlan, may next be noticed.

The body is here moderately elongated; the tail deep, and flattened at the sides; the head flat; the branchial tufts large. The limbs are four in number, and modeThe jaws and palate are furnished with small teeth. The toes are four on each foot.

rate.

The MENOBRANCHUS LATERALIS (see engraving) inhabits the great lakes of the Ohio and their tributaries; and attains, sometimes, to the length of three feet.

The MENOBRANCHUS TETRADACTYLUS is a distinct species. Of these singular creatures the habits are little known.

Dr. Harlan refers the Axolotl of Mexico to his genus Menobranchus; and, perhaps, correctly; but the toes are four before, and five behind. There are three long gills on each side in the form of tufts.

The AXOLOTL, (Siren pisciformis, Shaw; Menobranchus pisciformis, Harl.) is a native of Mexico; and common in the lake, out of which rises the city of Mexico itself. It is found in the coldest mountain waters, according to Humboldt, who, in his "Observations de Zoologie," has entered into minute details of its anatomy.

The engraving will convey a correct idea of this strange creature, respecting which naturalists have been greatly perplexed; many still doubting whether its gills are permanent; that is, whether it is not the Tadpole of a species, the perfect form of which is yet to be discovered. The length of the Axolotl is eight or ten inches; its general colour is grey, spotted with black. According to Hermandez, the flesh of this aquatic Reptile is very agreeable and wholesome, and resembles that of an eel.

GENUS SIREN.

The

We now come to the Sirens, (Siren, Linn.) These are eel-like animals, with three gill-tufts on each side; and utterly destitute of hinder limbs. The anterior limbs are feeble; and the toes small and clawless. head is flattened, the muzzle blunt, the mouth small. The lower jaw has teeth, the upper none; but there are ranges of teeth on the palate. The eye is very small; and the ear concealed.

The LACERTINE SIREN (Siren lacertina, Linnæus,) was discovered by Dr. Garden, who, in the year 1765, sent a specimen to Linnæus, with an anatomical description.

This species attains to the length of three feet, and is