“ In zoology the siren (Siren lacertina) , or “mud-eel” of the Americans, one of the perennibranchiate tailed batrachians, is the type of the family Sirenidae, chiefly distinguished from the Proteidae by the structure of the jaws, which, instead of being beset with small teeth, are covered by a horny sheath like a beak; there are, however, rasp-like teeth on the palate, and a few on the inner side of the lower jaw, inserted on the splenial bone. The body is eel-like, black or blackish, and only the fore-limbs are present, but are feeble and furnished with four fingers. ”