Olfactory apparatus similar to that of fishes, viz. a small aperture near the extremity of the snout leads into a cavity or _cul de sac_, lined by a delicate membrane, plentifully supplied by the fibrillæ of two slender olfactory nerves, which go off from the anterior end of each lobe of the cerebrum. The brain is of an oblong figure, the cerebrum is formed of two lobes, the cerebellum of one lobe situate directly posterior, not much thicker than the medulla oblongata. The optic nerves, which were large in proportion to the organs of vision, took their origin in a very unusual manner. On either side of the medulla oblongata, is given off a large nerve, which proceeds forwards and outwards, and soon after it passes outside of the cavity of the cranium, it divides into two branches, the smaller goes to the eye, the larger is distributed to the superior maxilla. The eye itself is small, and the lens which was coagulated by the spirits, is about half the size of a pin's-head, and of the texture of the lens of a fish when boiled. The number of vertebræ from the atlas to the last lumbar, is exactly nineteen; to the transverse processes of all of them (after the two first) is attached, by a movable articulation, a small slender spicular of bone, or rib-like process, about one-eighth of an inch in length, which at the same time, they give origin to the large muscles that move the body, offer no obstruction to the lateral curvatures of the animal when in motion, but as to appearance or function are not to be considered as ribs. The number of vertebræ from the first sacral to the last caudal, is from twenty to thirty-five; they become exceedingly small towards the end of the tail; on the back part of the œsophagus, exterior to the cavity of the cranium, is found on each side, a calcareous concretion, similar to that in the head of the shark.--JAMES. [005] Maclure.--JAMES. [006] Geological Survey of Rensselaer county, p. 11.--JAMES. [007] When central Pennsylvania began to seek an outlet for her population, the fertility of the soil produced by the disintegration of the limestone flooring of the northeast-and-southwest valleys of the mountains, and the barriers to Western migration imposed by the parallel ridges, directed most of the pioneers southwestward.--ED. [008] See Humboldt's Personal Narrative, vol. v. p. 46. Also St. Pierre's Paul and Virginia.--JAMES.