ART. 15 ANATOMY OF THE EARED AND EARLESS SEALS HOWELL 65 



(transversalis) cervicis. It sent tendinous slips to the transverse 

 processes of the first four thoracics and was tucked in laterad of the 

 trachelomastoid, inserting upon the dorsal part of the anapophyses 

 of the last four cervicals. 



M. trachelomastoideus* (figs. 2, 5), or longissimus capitis, although a 

 part of the long system morphologically, had better be considered 

 a separate muscle. In the Zalophus it arose from the postzygapoph- 

 yses of the last four cervical and first two thoracic vertebrae, and in- 

 sertion was strongly upon the mastoid process continuous with that 

 of the splenius. In the Phoca origin was from the third to seventh 

 (inclusive) cervicals. Miller reported that in his Phoca the muscle 

 was partially divisible, a second slip inserting upon the transverse 

 process of the axis; but nothing like this occurred in my specimen. 

 In Arctocephahis origin was from the last five cervicals only; in 

 E'umetopias from the fourth and fifth and in Odobenus^ the fifth 

 and sixth thoracic spines, according to Murie, who terms this the 

 splenius colli. 



flf. biventer cervicis (figs. 2, 17) in the Zalophus had origin by partly 

 tendinous slips from the postzygapophyses (or their vicinity) of 

 the first four thoracic and last two cervical vertebrae. Insertion was 

 upon the middorsal line for several centimeters caudad of the vei 

 lex, and for about two centimeters along the medial occipital border. 

 In Arctocephalus origin is said to be from the second, third, and fourth 

 thoracic vertebrae: In Odoherms "from the seventh dorsal'*; i» 

 Ev/rnetopms " from the fiftli, second, and first dorsal spines." 



M. complextts (figs. 2, 17) in the Zalophus arose by slips from the 

 vicinity of the postzygapophyses of the middle five corvicals, the one 

 to the sixth lying mediad of the cranial border of the biventer cei'vicis. 

 Insertion was rather narrow in a tendinous sheet for a couple of 

 centimeters along the occipital border laterad to the insertion of the 

 biventer cervicis. In Arctocephalus and Eunietopias origin is said 

 to be from the third to seventh cen- icals ; in Odohenus " from the fiftli 

 anterior dorsal." 



In my Phoca the biventer cervicis and complexus were indivisible, 

 forming the following : 



M. semispinalis capitis (fig. 3), arising in this Phoca from the vicinity 

 of the postzygajDophyses of the last six cervical and first two thoracic 

 vertebrae. It was a heavy muscle at origin, the fibers converging to 

 a thin, aponeurotic insertion upon the medial third of the occipital 

 crest. Miller, however, apparently had no trouble in separating 

 this muscle in his Phoca vitulina into a biventer and complexus, but 

 the attachments were very similar to those of mine. 



* It Is believed that in the case of the wood rat (Howell, 1926) the two divisions of the 

 blTcnter cervicis as stated should rather have been considered to comprise both that muscle 

 and the complexus, while the complexus, so termed, is in reality the tracehlomastoid. 



86377—28 5 



