30 



mid ulna were ossified to tlie liumerus. The following are the 

 dimensions of the humerus in our Sj^diiey specimens : — 



Whole length of humerus.. 



Breadth of head 



Breadth of narrowest part 

 Circumference of do 

 Breadth of extremity 



"With respect to the radius and ulna, they are hoth constricted 

 in the middle, and of much the same form, except that the 

 globular olecranon process of the latter gives a peculiar 

 character to this last, by its being very prominent as its turns 

 towards the thumb. The following are their dimensions : — 



Length of ulna 



Breadth of upper part of ditto, including the olecranon, whicl: 



projects so as to form a hook 



Circumference of narrowest part of ditto 



Breadth of lower part of ditto 



Length of radius 



Breadth of head of ditto 



Circumference of narrowest part of ditto 



Breadth of lower part of ditto 



The bones of the carj)us are not articulated together, as in the 

 more perfect mammals, but are imbedded in a mass of that 

 cartilaginous substance Avhich so often, in Cetacea, represents 

 bony matter. This flat mass of cartilage, which takes the place 

 of the wrist, is one foot two inches in width, and extends five 

 inches from the radius and ulna to the metacarpal bones. 



