348 ME. W. H. FLOWER ON THE OSTEOLO&Y OF THE SPEEM-WHALE. 



certain indications of difference. Each of tlie three vertebral columns which have 

 passed under more immediate observation shows certain peculiarities ; but what similar 

 part of the organization of any given species of animal will not do so 1 And it must be 

 remembered that, in these huge bones, differences of form and proportion are rendered 

 most conspicuous which would almost escape observation in specimens of the size of 

 those with which we are more accustomed to deal, and, further, tliat the ossification in * 

 the Sperm-Whale, more even than in other large Cetaceans, seems to have a special 

 tendency to exuberant and irregular development, producing a gi-eat amount of indivi- 

 dual character in the rugged masses composing the skeleton. 



It may be as well, however, to bring together the principal points of difference, such 

 as they are, in the three skeletons. The first to be mentioned relates to the length of 

 the column when the vertebrae are placed in close apposition. This is, in the Yorkshire 

 one, 29' 5", in the Caithness one (allowing for the missing caudal veitebraj) 29' 3", in the 

 Tasmanian one 30' 4". It must be remarked that the last, though the longest, is the 

 least mature of the three animals. In the first two the con-espondence is exceedingly 

 close. With regard to the third, something must be probably allowed for the fact 

 that the loose epiphyses of the ends of the vertebrae, having become detached in 

 maceration, could not be made to fit again so closely as they would if ank)dosed ; and 

 hence the length of each vertebra was increased to a very slight extent. The differ- 

 ences in the proportions of the individual vertebrae are given in the Table at p. 327. 

 They are not inconsiderable, but are as great in the case of the two British specimens 

 as between either of these and the Tasmanian one. The greater height of the lumbar 

 vertebra of the two former as compared with the latter, is chiefly due to the increased 

 development of the keel of the body, apparently a consequence of superior age. Slight 

 differences in the atlas, chiefly relating to the form of the lower part of the central 

 opening, and to the development of the transverse processes, have been already spoken 

 of in the description of that bone. 



In the annexed Table I have given the vertebral formula of the principal members 

 of the group of Delphinoid Cetaceans, as far as I have been able to ascertain them from 

 perfectly reliable sources. 



Physeterid^. 



Phjseter macrocephalus australis (Mus. Eoy. Coll. Surg.), C. 7, D. 11, L. 8, C. 24=50. 

 P. macrocephalus australis (Wall), C. 7, D. 10, L. 8, C. 24=49. 

 P. macroceplialus horealis (Yorkshire), C. 7, D. 11, L. 8, C. 23=49. 

 Kogia grayii (Wall), C. 7, D. 14, L. C. 30 = 51. 



Hiiperoodo7i rostmtum (Mus. Oxford and Vrolik), C. 7, D. 9, L. 10, C. 19 = 45. 

 H. rostratum (Amsterdam and Roy. Coll. Surg.), C. 7, D. 9, L. 10, C. 18=44. 

 Micropteron soiverbyense (Van Beneden), C. 7, D. 10, L. 10, C. 19 = 46. 

 Ziiihhis mjptodon (Burmeister), C. 7, D. 10, L. 12, C. 20=49. 



