364 



ME. "W. H. FLOWER ON THE OSTEOLOGY OF THE SPEEM-WHALE. 



proportion to its length, and having less of the hourglass-shape, its outer border being 

 nearly straight. It is followed by three phalanges, which rapidly decrease in size. 



Pelvis. 



In all known Toothed Whales the sole rudiment of a pelvis is formed by a pair of 

 elongated subcylindrical bones {ossa ischia) placed horizontally and nearly parallel to 

 the vertebral column*, opposite to the junction of the lumbar and caudal regions, and 

 giving support to the crura of the penis or clitoris, as the case may be. In no species 

 of this group have any such accessory bones or cartilages representing the hinder 

 extremities, as those discovered by Reinhardt in Balwna mysticetus, and subsequently 

 by other observers in several of the Whalebone-Whalesf, been hitherto observed. It 

 must be remarked, however, that they have never been looked for with much care in 

 any of the larger members of the group, as the Cachalot or Hyperoodon. 



The description and figure given by WallJ, which represent each lateral half of the 

 pelvis of a young female Cachalot as composed of two bones, placed end to end, does not 

 accord with the general observation upon the more common Dolphins, that each of the 

 ischial bones ossifies from a single centre. Unfortunately I have no materials to con- 



* In the Porpoise, their anterior extremities diverge from each other. 



t Eschricht, Nordisch. Wallthiere, p. 136 ; W. H. Flower, Proc. Zool. Soc. 1865, p. 704. 



J Op. cU. p. 32, and pi. i. fig. 4. . 



