228 



THE SHOULDER GIRDLE. 



[chap. 



narrow, but flattened. The spine sends a flat process back- 

 wards near its middle, and a long slender '^ metacroniiaV 

 process from its extremity. The clavicle is very long, slender, 

 and curved. The " mesoscapular segment " forms a distinct, 

 though minute, bone between the clavicle and scapula. 



In the Shrews (Soricidce) the scapula (see Fig. 74) is 

 also long and narrow, and the slender acromion ends in 

 two long diverging processes, of which the anterior (a) 

 supports the clavicle and the posterior {ifia) is called 

 " metacromion." The mesoscapular segment (niss) is a 



F'iG. 74. — Shoulder girdle with upper end of sternum (inner surface) of Shrew {Sorex), 

 after Parker, x 7. ps presternum ; sr^ first sternal rib ; sr'^ second sternal rib ; 

 ec partially ossified " epicoracoid" of Parker, or rudiment of the sternal extremity 

 of the coracoid ; ost omosternum ; pc rudiment of precoracoid (Parker) ; cl cla- 

 vicle ; inss ossified "mesoscapular segment;" a acromion; 7iia metacromial 

 process ; c coracoid. 



distinct bone. The clavicle {d) is long and slender. It has 

 a small piece of cartilage (/r) attached to its inner end. 

 The omosternum (ost) is cartilaginous or partially ossified, 

 and there is a considerable triangular flattened rudiment 

 of the inner end of the coracoid {ec) attached to the pre- 

 sternum. 



In the other Insectivora the general form of the scapula 



