of the Pelecanus Aquilus of Linnams. & 



longest dimension being about an inch. Its body is thin and 

 transparent, consisting of two lamellae ; towards the root, where 

 it is attached to the vertebra?, it becomes thicker, and has seve- 

 ral perforations ; on the lower edge it has two depressions, which 

 receive the spinous processes of the fifth and six vertebrae. This 

 bone intervenes between, and serves to support two fatly masses 

 or cushions, of a firm consistence and having almost a elan- 

 dular appearance, into which the roots of the great tail-feathers 

 are inserted ; these lie on the outer surface of the lateral pro- 

 cesses of the vertebrae. To various parts of these masses and 

 to the lateral processes of the vertebra? are attached seven di- 

 stinct pairs of muscles for regulating the action of the tail, which, 

 as has before been observed, appear to be of vital importance 

 to the bird. The upper and largest pair arises fleshy from the 

 dorsum of the pelvis, and tendinous from the back of the lateral 

 processes of the vertebrae, and is inserted into the fatty Glasses 

 before mentioned: four pairs of muscles of less size also arise 

 from the lower edge of the pelvis, and from the ends of the up- 

 per lateral processes, and have their attachment to the same 

 parts : and two pairs have their origin from the inner surface ol 

 the bodies of the vertebrae and the lower edge of the pelvis, and 

 are attached close to the termination of the tail-feathers. It is 

 apparent that the action of these muscles, either separately or in 

 their different combinations, is equal to that variety of action, 

 which it has been one of the objects of this paper to prove to be 

 indispensably necessary to the bird's existence. 



The muscles of the upper extremities are large in proportion 

 to the bones. The two great pectoral muscles alone are of so 

 enormous a size as to weigh nearly one-fourth as much as the 

 whole body of the bird. 



The liver occupies the greater part of the abdomen, and is 

 divided into two lobes of nearly equal magnitude, of much 



vol. xui. c greater 



