156 



AiXA TOMICAL TECBNOL OGY. 



,§ 893. Delta Mes/)scapul(B — The delta of the mesoscapula (Fig. 44), — We suggest this 

 as a suitable designation of the slightly elevated triangular rough surface at the vertebral 

 end of the mesoscapula. 



§ 394. Fossa Infraspinata — The infraspinous fossa. — This is the larger of the two ectal 

 fossae, and is distinctly triangular in shape. It is overhung by the mesoscapula and 

 metacromion. 



§ 395. Fossa Supraspinata — The supraspinous fossa. — This is less regular in form than 

 the infraspinous fossa, and its area is less extensive ; but the muscle which occupies it is 

 larger than might be inferred, both on account of the inclination of the mesoscapula and 

 its own projection beyond the coracoid border of the scapula. 

 Mesoscapula — Spine of the scapula. — See above (§ 390). 



§ 396. Metacromion — (Fig. 43, 67). — At its greatest elevation, near the glenoid end, the 

 mesoscapula is produced over the infraspinous fossa as a quadrate or subtriangular pro- 

 cess, the metacromion. Its ectal surface and free border are rough for the insertion of the 



MM. legator clamculm and acromio- 

 A, GkjioicC ind. of ri^ht scapula.. 

 Tbe.L, bicipltaie 

 Acromion., 



Prt.coracoiaeus. 

 -fossa, gltnoidea. 



MeCacromicn 



fossa, 

 tirathitenana— 



trapezius. 



§ 397. Tuberositas [Mesoscapula) — 

 The tuberosity of the spine of the 

 scapula. — At about midway between 

 the tip of the acromion and the delta 

 the mesoscapula is thickened and 

 roughened, constituting the tiiberosity. 

 § 398. Explanation of Fig. 45, 

 A. — This shows the glenoid end of a 

 right scapula. The bone is so placed 

 that the acromion appears 1 ess pointed 

 than the metacromion, the infraspi- 

 nous surface of the mesoscapula is 

 much foreshortened, and only a part 

 of the glenoid border is shown ; the 

 coracoid border is not represented at 

 all. 



Between the acromion and the ectal 

 margin of the Fs. glenoidea is a deep 

 notch, the Incisura magna (scapuiaris), 

 or " great scapular notch." 



§ 399. Fossa Glenoidea. — This is 

 seen to be a shallow concavity with a 

 pear-shaped outline. The smaller end 

 forms a distinct Tbcl. (tuhcrculum) bi- 

 ciijitale for the attachment of the M. 

 biceps at the root of the Pre. (processus) coracoideus. Near this end, the ental border of the 

 fossa presents a slight emargination. 



§ 400. Pre. (processus) Coracoideus — The coracoid process. — This shows here to the 

 best advantage as a hook-like process comparable with the beak of some birds (whence its 

 name), or with a half-bent finger, as suggested by Humphrey (A, 366). At its base, oppo- 

 site the emargination near the smaller end of the Fs. glenoidea, is a nutrient foramen. 



§ 401. Explanation of Fig. 45, B.— This represents the proximal end of a right 

 humerus, with the dorsal side uppermost. When, therefore, the humerus and the scap- 

 ula are in contact at the shoulder, the upper and narrower part of the arthral surface of 

 the former is received by the lower and wider part of the Fossa glenoidea. 



B. Head 0/ CtyAt h amir us. 

 Fig. 45. — The Glenoid End of an Adult 

 Eight Scapula (A), and the Proximal 

 END 01" AN Adult Eight Humerus (B); 

 slightly reduced. 



