NOTES ON THE ANATOMY OF A SEAL — SOMMERS. 157 



eyes fine dark prominent, with a strong nictitating membrane, 

 which in the dead animal could be made to cover two-thirds of 

 the globe, nostrils closed by valves or folds of mucous membrane, 

 external ear without appendages, the meatus opening by an oval 

 aperture upon the skin of the head in the position usual in mam- 

 malia, the meatus was beset with soft bristles, depth of canal of 

 external ear, i. e. from meatus to typanum one and one half inches, 

 the body on the removal of the integument presented a well 

 nourished appearance, the sternum was prolonged upwards to the 

 top of the larynx by a cartilaginous extension, this measured three 

 and one half inches above the clavicles, and gave origin in its 

 whole length to portions of both pectoral muscles, these muscles 

 arose as in the human subject from the sternum and ribs in front, 

 but the great pectoral was continued downward to the point of 

 the ziphoid cartilage, their insertions the same as in man, viz : to 

 the clavicle humerus and scapula, the positions of other thoracic 

 muscles are so similar to the corresponding parts in human 

 anatomy I deem it to be unnecessary to proceed with their des- 

 cription. 



The development of these muscles in the seal corresponds more 

 to the same in birds than in land mammals, the shoulder muscles 

 are also correspondingly developed, the trapezius very thick, 

 deltoid and biceps, short, thick, and strongly attached to the 

 bones, these points in the myology of the seal can be seen only 

 on dissection, they are covered by the general integument nearly 

 down to the wrist joint, as however the integument is loose 

 the bones short and articulated at opposing angles, there is much 

 freedom of movement in the anterior limbs. 



The modification of the bones at the extremities, furnishes a 

 most striking peculiarity in the anatomy of the seal ; in the superi- 

 or, the scapula is broad, rounded at the edge, bearing some re- 

 semblance to the same bone in man, the fossa? for the supra and 

 infra spinati muscles are deep, the under surface of the bones 

 are deeply concave for the lodgment of the large sub-scapulars, 

 the humerus very short and thick, the ulna and radius also short, 

 but the olecranon process of the ulna is much prolonged to afford 

 attachment for the powerful extensors of the arm, the metacarpal 



