VII.] EDENTATA. 83 



In the Manati (Manatus) the sternum is of somewhat 

 similar form, and has three pairs of ribs attached to its 

 lateral margins near the middle. 



Among the Edentata there is considerable variation in 

 the characters of the sternum. 



In the Cape Anteater (Orycteropus) the sternum is of 

 quite a normal form. The presternum is trefoil-shaped, 

 expanding laterally near the front to meet the largely de- 

 veloped clavicles, then contracting to the width of the 

 mesosternal segments, which are four in number, simple, 

 flattened, oblong, with lateral margins nearly parallel, 

 rather broader above than below, united together by fibrous 

 tissue, and succeeded posteriorly by a moderately deve_ 

 loped xiphisternum. 



fin Mam's dalmannii the sternum is flat, consisting of 

 i'en segments, several of which are sometimes divided 

 the middle line by synovial cavities. The xiphisternum 

 very long, partially cleft in the middle line, and ending 

 in a large, flattened, cartilaginous expansion. In the Long- 

 tailed Pangolin (Mam's longicanda) the xiphisternum is of a 

 remarkable form, being prolonged into a pair of cartila- 

 ginous processes, each about nine inches long, and con- 

 nected posteriorly with some rudimentary abdominal ribs. 1 



In the Anteaters (Myrmecophagd) the presternum is broad, 

 flat, and oval. The segments of the mesosternum (Fig. 42) 

 are eight in number, short, deep, broad above, and sending 

 a club-shaped process downwards ; each is ossified from a 

 principal endosteal centre and eight epiphyses, is connected 

 by synovial articulations with the segment before and behind, 

 and has at either end an upper and lower hollowed surface, 

 which, with the corresponding surfaces on the contiguous 

 segment, form articulating facets for the double- headed I 



I 1 Parker, op. cit. 

 G 2 



