XVI. J 



CETACEA. 



273 



granules, so irregularly or im- 

 perfectly ossified, and so easily 

 lost in cleaning, that it is in 

 many cases impossible, when 

 describing the skeleton of one 

 of these animals^ to give the 

 exact number of phalanges to 

 each digit. 



The determination of the 

 homologies of the carpal bones 

 of the Cetacea with those of 

 other Mammalia is beset with 

 difficulties, and has conse- 

 quently led to some differences 

 of opinion among those anato- 

 mists who have attempted it. 

 Moreover every species ap- 

 pears liable to certain indivi- 

 dual variations, and sometimes 

 the different sides of the same 

 animal are not precisely alike, 

 either in the arrangement, or 

 even the number of the carpal 

 ossifications. 



The pisiform is occasionally 

 represented by a small ossifi- 

 cation on the ulnar border of 

 the carpus. Excluding the 

 above, the carpus of the Odon- 

 tocetes appears never to con- 

 sist of more than six bones, 



three belonging to the proximal, and three to the distal 

 row. 



Fig. 99. — Dorsal surface of bones of 

 ri2;ht anterior limb of Round-headed 

 Dolphin (Globiocephnlus ji/clns), j^. 

 The shaded portions of the digits are 

 cartilaginous. 



