ART. 15 ANATOMY OF THE EAEED AND EARLESS SEALS HOWELL 



49 



insertion upon the anapophysis of the fourth cervical vertebra. (2) 

 was even Aveaker, extending from the first rib to the anapophysis of 

 the fifth cervical, possibly with a few fibers to the fourth as well. 

 In the Pkoca there were three divisions, (i) arose by digitations 

 from the third to fifth ribs. The one from the fifth arose deep to 

 the most cranical slip of the serratus magnus. There was a dorsal 

 slip superior to the most caudal digitation of the depressor scapulae 

 and another ventral one, both arising from the fourth rib, besides 

 a single ventral slip arising from the third rib. The fibers of all 

 converge to form a tapering, cylindrical muscle which was strongly 

 inserted by tendon upon the anapophysis of the third cervical only. 

 (2) arose from the first rib and was inserted upon the anapophyses 

 of the fourth, fifth, and sixth cervical vertebrae. {3) also arose 



Fig. 15. — Left aspect of Zalophus (Z) and Phoca hispida (p) showing pl.\tysma- 



PAXNICULUS CARNOSU.S SHEET OF MUSCULATURE 



from the first rib but dorsad of the second division. Insertion was 

 by fibrous digitations upon the anapophyses of the third, fourth, 

 fifth, and sixth cervicals. In Eumetopias Murie found that inser- 

 tion of the two divisions v/as upon the sixth and seventh cervicals ; in 

 Odobenus that the muscle was single, from the third and fourth ribs 

 to the atlas. Miller gave two divisions for Arctoceflidlus and three 

 for P. vitulina. The latter was much as I found it in my specimen, 

 save that insertion was said to be on the parapophyses of the cervical 

 vetebrae. Both origins and insertions of Arctocephalus were given 

 as very much more extensive than in my Zalophus. 



M. longus colli in the Zalophus may be said to occur in three por- 

 tions, but the anterior or atlantic one was exceedingly complex. Its 

 cranial part lay directly laterad of the rectus capitis anterior major 

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