M. OCCIPITO-SCAPULARIS. 317 



while in other cases the muscle extends mesad of the bone so as to 

 join the border of the ectopectoralis. 



Pull the muscle dorso-cephalad, and note its apparent continua- 

 tion across the clavicle with the clavo-deltoideus. Q'he muscles, 

 however, are joined by a raphe, the trapezio-deltoid, which is more 

 apparent upon the ental aspect. Most of the clavo-trapezius is 

 inserted upon this raphe ; but the ental fibers of the cephalo-ventral 

 third or fourth are attached directly to the ventral border of the 

 sternal and straighter half of the clavicle. Variations in the mode 

 of insertion should be noted, drawn and reported. 



M. OCCIPITO-SCAPULARIS. 



§ 617. Synonymy. — There seems to be some doubt as to its human homologue ; rJiom- 

 boideus capitis, Miv., B, 145, and Wood, 9, 93, Fig 33, " d" ; occipito-acapulaire, S.-D., A, 

 II, 331 ; pai-t of rhombnde, Ch., A, 203 ; part of rkomboideus, Ch. (Fl.), A, 188. 



Figures. — Slightly at the dorsal end of the hiatus trap:zii (66) ; ecfal aspect (67) ; 

 lateral border (73) ; insertion area (45). 



Exposure. — by the removal of the MM. acromio- and clavo- 

 trapezius. 



General Description. — Narrow, tseniate, near — and nearly par- 

 allel with — ^the dorsimeson, from the crista lamhdoidalis to the 

 coraco-vertebral angle qf the scapula. 



Dissection. — About midway between the occiput and the scapula 

 the lateral border of the muscle appears as a slightly raised line 

 10-15 mm. from the meson. Trace it nearly to the occiput. Lateri- 

 duct the middle of the cephalic half of the muscle so as to indicate 

 its mesal border ; then transect. 



§ 618. Origin.— By fleshy fibers from the crista lambdoidalis, 

 entad of the origin of the clavo-trapezius, beginning 5-10 mm. from 

 the meson, and extending 12-15 mm. laterad to a point nearly in 

 line with the temporo-parietal suture (§ 49B), where it is overlapped 

 by the dorsal border of the sterno-mastoideus. Caudad, the mtfs- 

 ele gradually approaches the lateral border of the rhomhoideus. 

 At the junction of the third with the last fourth, the muscle narrows 

 and thickens, so as to become prismatic rather than tseniate. 



Insertion.— The narrowing muscle is wedged pretty closely 

 between the rTiomboideus at its mesal side and the levator anguli 

 scapulcB at its lateral side, and is inserted either between these mus- 

 cles upon the coraco-vertebral angle of the scapula (Fig. 45), 6-16 

 mm. cephalad of the mesoscapula, or upon the ental surface of the 



