66 PEOCEEDIXGS OF THE NATIONAL MUSEUM vol 7i 



M. rectus capitis posterior major (figs. 2, 3) in the Zalophus arose not 

 only from the whole length of the spine of the axis but also from the 

 periosteum over the spine of the third cervical. Insertion was upon 

 the supraoccipital laterad to the border of the biventer cervicis. In 

 the Phoca it was larger and covered both the minor division and the 

 inferior oblique as well. Origin was from practically the entire 

 length of the axial spine and insertion was upon the occiput from 

 the vertex almost to the lateral margin of the semispinalis capitis 

 insertion. In Arctocepluilus and Eumetopias origin was confined to 

 the axis. In Odohenus it also '' has attachments to the five posterior 

 cervical zygapophyses." 



M. rectus capitis posterior major acessorius (fig. 3), so termed b}' Miller 

 and Murie for the animals which they dissected was not distin- 

 guished in the Zalop/ms, but in the Phoca arose from the cranial 

 border of the axial spine, with insertion upon the occipital between 

 tlie superior oblique and minor rectus. 



M. rectus capitis posterior minor (figs. 2, 3) lay deep to the last. It 

 took origin from the dorsal arch of the atlas and inserted upon the 

 supraoccipital deep to the last. In the Phoca it was similar save that 

 the insertion was situated mediad to the accessory part of the major 

 division. 



M. obliquus capitis superior (figs. 2, 3) arose from the transverse 

 process of the atlas, with insertion strongly upon the lateral part 

 of the occipital plane. 



M. obliquus inferior in the Zalophus arose from the spine of the axis 

 deep to the rectus major, with insertion upon the transverse process 

 of the atlas. In the Phoca it seemed to be easily divisible into two 

 similar parts. Miller found it single in his Phoca., however. 



The perineal muscles were not investigated but it was noted that 

 the levator ani, apparently occurring in two divisions, was poorly 

 developed, or rather that the fibers were coarse and separated by 

 much fatty tissue. 



MUSCLES OF THE ANTERIOR LIMB 



MUSCLES OF THE SHOULDER GIRDLE 



M. supraspinatus (figs. 7, 9, 16, 19, 20, 21) was complex in the Zalo- 

 phus^ as is often the case. Origin was from the entire supraspinous 

 fossa and anterior surface of the spine. Near the insertion it was 

 separable into two slips, the more dorsal inserting upon the tip of 

 the greater tuberosity with a few fibers passing also to the lesser. 

 The second slip inserted upon the greater tuberosity also, just distad 

 of the tip. In the Phoca origin was the same, and the muscle was 

 partially divisible ectad, as indicated in Figure 21. Insertion was 

 upon the greater tuberosity and upon the ligament extending from 



