Rocky Mountains. 7 



tain chain extends uninterrupted along the Atlantic coast, from 

 the Gulf of St. Lawrence southwest to the great alluvial 

 formation of the Mississippi. It crosses the St. Lawrence 

 at the rapids above Quebec, and has been supposed to be 

 connected as a spur to a group of primitive mountains occu- 

 pying a large portion of the interior of the continent, north 

 of the great Lakes.* An inspection of any of the late maps 

 of North America, will show that this range holds the se- 

 cond place among the mountain chains of this continent. 

 All our rivers of the first magnitude have their sources, either 

 in the Rocky Mountains, or in elevated spurs, projecting from 

 the sides of that range. The largest of the rivers, flowing 

 from the Alleghanies, is the Ohio ; and even this, running al- 

 most parallel to the range, and receiving as many, and, with 

 a few exceptions, as large rivers from the north as from the 



differing from the amphibia, in which there is either a double or mixed 

 circulation. 



Olfactory apparatus similar to that of fishes, viz; a small aperture near 

 the extremity of the snout, leads into a cavity or cut de sac, lined by a de- 

 licate membrane, plentifully supplied by the fibrillse of two slender olfac- 

 tory nerves, which go off from the anterior end of each lobe of the cere- 

 brum. 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 vertebra? 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 moveable 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 vertebras from the first sacral to the last caudal, is from twen- 

 ty to thirty-five; tbey become exceedingly small towards the end of the 

 tail; on the back part of the esophagus, exterior to the cavity of the cra- 

 nium, is found on each side, a calcarious concretion, similar to that in the 

 head of the shark. 



* Maclure. 



