AET. 15 ANATOMY OF THE EAKEU AND EARLESS SEALS HOWELL 59 



tral third it was intimately attached by fasciculi. Near the insertion 

 its cranial border was overlapped by the cephalohumeral. It in- 

 serted, mostly deep to the latter, along the entire deltoid ridge of the 

 humerus and its distal border extended even as far as the forearm, 

 the fibers not ending in fascia but seeming to be incorporated with 

 the supinator longus in company with the deltoid. In the Phoca 

 this muscle did not overlie the spine. It arose from the middorsum 

 from mediodorsad of the spine almost to the occiput, this being 

 partially deep to the caudal border of the cephalohumeral. Inser- 

 tion was robustly along the entire spine of the scapula and also by 

 fascia along the caudal border of the deltoid ridge as far distad as 

 a crater-like fossa, into which inserted a stout tendon which diverged 

 from the humerotrapezius farther dorsad. For Arctocephalus 

 Miller's description is not entirely clear, but the muscle seems to 

 resemble that of my Phoca; and Euinetopias also conforms largely 

 to this iDattern — certainly not to that of Zaloflius. On the other 

 hand conditions in the latter genus were very similar to what Murie 

 encountered in Odohenus. 



M. spinotrapezius (figs. 7, 16, 17) was long and slender, arising from 

 the middorsum toward the caudal thorax. In the case of the 

 Zalop/ms there was a deep, tough aponeurosis upon which most of 

 the fibers inserted, but more ectad there was a flat tendon developed 

 and this ran cranio-ventrad to the spine near the ventral border of 

 the muscle. That of the Phoca was similar save that the muscle 

 fibers inserted directly upon the spine. In Arctocephlus insertion 

 is said to be by the fibers blending with the dorsal surface of the 

 deltoid. 



M. latissimus dorsi (figs. 9, 16, 17) in the Zalophus arose from the 

 dorsal fascia, extending from a few centimeters craniad of the 

 glenovertebral angle of the scapula to the vicinity of the last rib. 

 The anterior border passed superficial to the glenovertebral angle 

 and the fibers of the whole sheet converged to two partially separable 

 insertions — the more dorso-cranial one, representing perhaps two- 

 thirds of the muscle, to a fascial insertion along the border of the 

 teres major, and the other, to a fleshy insertion along the dorsal 

 border of the insertional end of the pectoralis. For Ewnetopms 

 this muscle was reported as single, with insertion upon the bicipital 

 ridge. Its insertion was not given for Odohenus. In the Phoca the 

 dorso-cranial part was quite thin, with origin gradually from the 

 dorsal fascia and fibers converging to the axillary tissue. The ven- 

 tral part was rather abruptly 10 times as thick as the remainder, 

 with insertion upon the deltoid ridge with the second and third 

 divisions of the pectoralis. 



M. rhomboideus anticus (figs. 2, 3, 7, 16, 17) in the Zalophus arose 

 from the medial third of the occipital crest deep to the cephalo- 



