352 



BREAST BONE 



vertebra, though hardly at all marked, is nevertheless really 

 present and developed from a bony centre of its own, as in other 

 mammals. The dorsal and lumbar vertebrae are, of course, to be 

 distinguislied by the presence of ribs attached to the former ; but 



sn 



Fig. 186. — Section tliroiigli middle 

 line of nnited cervical vertebrae 

 of Greenland I light Whale {Bal- 

 aena mysticetus). x i. a, Arti- 

 cular .surface for occipital condyle; 

 e, epiphysis on posterior end of 

 body of seventh cervical vertebia ; 

 S7i, foramen in arch of atlas for 

 first spinal nerve ; 1, nrch of atlas ; 

 2, 3, 4, 5, t3, conjoined arches of 

 the axis and four following verte- 

 Virae ; 7, arch of seventh vertebra. 

 (From Flower's Osteology.) 



as there is only a rudimentary pelvis, not attached to the 



vertebral column, no sacral region can be detected. Tlie caudal 



vertebrae are to l)e recognised l)y the V-sliaped chevron bones 

 below. 



•4" ■ 



Fig. 187. — A, Sternum of Greenland Riglit Whale {Balaena mysticetus). x 

 Sternum of Common Korqual or Fin Whale {Balaenoptera musculus). 

 (From Flower's Osteology. ) 



B, 



The sternum in the Whale tribe is much more modified in the 

 Whalebone Whales than in the Odontocetes. In the latter it is 

 made up of several pieces, as in other manmials, which often, 

 however, become coalesced. In tlie Mystacoceti this bone is a 

 single piece, to whicli only one pair of ribs is attached, and its 



