OSTEOLOGY 



119 



In Neotoma the prelambdoidal fenestration of the squa- 

 mosal is considerably the smallest, and this either may indi- 

 cate that the mastoid process of the squamosal is weaker, 

 or it may be fortuitous as far as muscular development is 



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Fig. 25. A, Lateral aspect of left mandible of Teonnma, showing areas 

 of muscle attachments. B, Sternum of Teonoma. C, Hyoid of Homo- 

 doniomys, showing (o) body, (6) greater cornu, and (c) lesser cornu. 



concerned. This mastoid process is heavier in Teonoma, 

 which should indicate greater strength of the attached 

 sternomastoid, cleidomastoid, and complexus muscles. 



The differences exhibited by the mandibles of the three 

 animals are relatively slight. In Teonoma the lower jaws ap- 



