[004] _Triton lateralis._ SAY.--_Body_ and extremity above brown, with irregular black spots; _tail_ much compressed, subacutely edged above and beneath, lanceolate; a black vitta from the nostrils passes through the eyes, and is dilated on the sides, and becomes obsolete on the tail; a vertebral indented line, from the neck to the origin of the caudal carina, more faintly indented on the head; _head_ somewhat rectilineary attenuated from the anterior branchia, to the vicinity of the nostril, and truncate or subemarginate before; _nostrils_ minute; _eyes_ very small, whitish, crossed with the lateral line of the head; _beneath_ pale flesh-colour; _chin_ and _jaws_ to the branchia, and _tail_ from the posterior feet, with the exception of the areola of the anus, coloured like the back; _mouth_ moderate, angles beneath the eyes; _lips_ covering the jaws freely, inferior lip with a duplicature each side, which is white and covered by the superior lip; _tongue_ free, fleshy, rounded, extending beyond the angles of the mouth; _teeth_, lower jaw in a single row, obtusely conic, small, rather distant; a few smaller ones near the angle, elevated on a slightly prominent portion of the jaw; _superior jaw_, with a double series of teeth similar to the others, but rather smaller, an unarmed depression corresponding with the elevation in the lower jaw, and a few elevated teeth nearer the angle; _throat_ with a duplicated cuticle; branchiæ permanent. Legs short, weak, four-toed. Total length 10 inches, from the tip of the nose to the vent, 6-1/2 inches. We caught this animal with the hook and line in the neighbourhood of Pittsburgh, but it is by no means so common there as the Salamandra Alleghaniensis of Michaux, or young alligator. The colour above is in reality pale, but it is rendered of a brownish appearance by the very numerous confluent points of that colour, which nearly cover the surface of the body; branchia bright red; peduncles colour of the body. Daudin informs us, that Schneider, in his history of Amphibia, describes an animal very similar to this, found in Lake Champlain, and which Daudin supposes to be the larva of _Triton Alleghaniensis_; Daudin, however, is of the opinion, that the hind feet were mutilated, from the circumstance of their having only four toes. The late Professor B. S. Barton had heard of this animal, and from the account he received, was led to regard it as a Siren. Finally, Dr. Mitchell has autoptically described the animal, in the 4th vol. of Silliman's Journal, as a Proteus.