CETACEA. 



745 



cusped teeth. No clavicles are developed. The bones of 

 the fore-limb are flattened, and, except at the shoulder, 

 articular surfaces are not developed, so that the limbs form 

 stiff paddles. The carpals are fixed in a fibrous matrix, 

 tend to be rudimentary, and are often unossified. They 





FIG. 367. Left fore-limb of 

 Balcsnoptera. 



V., Scapula with spine (.</.); H.. 

 humerus ; R., radius ; /.,idna ; 

 C., carpals embedded in matrix ; 

 Jfc., metacarpals ; PJi., phal- 

 ange?. 



FIG. 368. Fore-linil) 

 of whale (Megaptera 

 longimana}. After 

 Struthers. 



cannot be readily compared with the members of the 

 typical mammalian carpus. In the absence of true joints, 

 a slight flexibility is given by the absence of ossification. 

 There are four or five nailless digits, of which the second 

 and third, and sometimes the first, may have more than 

 the usual number of phalanges (see Fig. 368), a peculiarity 



