232 THE SHOULDER GIRDLE. [chap. 



with a very narrow base of attachment, projecting for- 

 wards ; the coracoid (c) is rather long, flattened, and parallel 

 with the acromion. 



In the Cachalots (Physeter) the scapula is formed on the 

 same general plan, but is comparatively high and narrow. 

 The postscapular fossa is very concave, and the sub- 

 scapular fossa convex. The Gangetic Fresh-water Dolphin 

 (P/atanista) has a flat flabelliform scapula, with the pre- 

 scapular fossa entirely absent, and the acromion placed on 

 the anterior edge, the spine and the coracoid border having 

 coalesced. 



Among the Whalebone Whales, Balcenopiera has a broad 

 fan-shaped scapula, like that of the true Dolphins, with 

 long parallel acromion and coracoid processes, and a supra- 

 scapular border which remains permanently in a cartilaginous 

 condition. In the Right Whales (Balcena) the scapula is 

 more massive and not so broad, and the coracoid is much 

 reduced. In Megaptera the scapula is triangular, and neither 

 the coracoid nor the acromion forms a distinct process. 



None of the Cetacea possess clavicles. 



The scapula of the Sirenia is formed on quite a different 

 plan, being rather like that of the Seals in shape, narrow, 

 and curved backwards. The anterior fossa is nearly as 

 large as the posterior. The spine is moderately developed, 

 and the slender acromion points downwards. The coracoid 

 forms a moderate-sized conical process. There are no 

 clavicles. 



In the Ungulata the scapula is always high and rather 

 narrow. The prescapular and postscapular fossae are often 

 subequal. The acromion and coracoid are never much 

 developed. The clavicle is always absent. 



The Pecora (see Fig. 77) have all a very large and very 

 slowly and imperfectly ossified suprascapular region (ss) ; 



