570 



PHOCA VITULINA HARBOR SEAL. 



to the small size of these vertebrae, but in part to their reduced 

 number.* 



Measurenientaof the principal parts of the skeleton in Phoca vitulina, Phoca grcm- 



landica, and Phoca fceiida. 



Principal parts. 



Length of the skull 



1 Length of the cervical vertebraa 

 I Length of the dorsal vertebrae . . 

 j Length of the lumbar vertebrae. 



Length of the sacral vertebrae 1 . 



Length of the caudal vertebrae . 



Length of the scapula 



Length of the hvunems 



j Length of the radius 



' Length of the manna 



Length of the pelvis 



: Length of the femur 



I Length of the tibia 



Length of the pes 



o 



220 

 210 

 445 

 216 

 120 

 230 

 135 

 114 

 105 

 145 

 200 

 112 

 200 

 270 



1 

 bO.' 



o 



o 



c8 



o 



o 



210 

 240 

 510 

 255 

 100 

 317 

 152 

 123 

 130 

 145 

 255 

 109 

 255 

 313 



163 

 200 

 410 

 190 

 100 

 245 

 137 

 100 



95 

 128 

 170 



94 

 190 

 250 



* The vertebral formulae of the five species of northern Phocids, of which 

 I have before me several complete skeletons of each, are as follows : 



Species. 



Cervical 

 vertebrae. 



Dorsal 

 vertebrae. 



Lumbar 

 vertebrae. 



Sacral 

 vertebrae. 



Caudal 

 vertebrae. 



Phoca vitulina 



Phoca foetida 



Phoca groenlandica . . , 

 Erignathus barbatus 

 Cystophora cristata. 



15 

 15 

 15 

 15 

 15 



10 

 14 

 13 

 13 

 10 



The number of sacral and caudal vertebrae, especially the latter, may be 

 subject to individual variation, as Gerrard (Cat. Bones of Mam. iu Brit. 

 Mu8., 1862, p. 143) gives 3 sacral and 12 caudal for P. vitulina. Lilljeborg 

 also gives only 3, but adds that a very old skeleton has 4. In each of the 

 four skeletons of this species which I have examined 4 vertebrae are firmly 

 anchylosedto form the sacrum; in three of these the caudal series is imper- 

 fect. Gerrard gives also only 3 sacral for Erignathus barbatus (Ibid., p. 145), 

 while in two skeletons I find 4 in each. 



Lilljeborg gives the length of the tail in Phoca vitulina at 69 mm.- and in 

 Phoca foetida, male, 150 mm., female, 144. 



t In two very old skeletons of Phoca groenlandica I find the sacrum to con- 

 sist of only three anchylosed vertebrae. In both the other species the sa- 

 crum consists of four anchylosed vertebrae. 



