344 



PATAGONIAN EXPEDITIONS I PAL/EONTOLOGY. 



inner humeral epicondyle is perforated by a large foramen in Thylacymts, 

 Prothylacynus and Cladosictis; imperforate in AnipJiiproviverm. In Pro- 

 thylacynus, the supinator ridge terminates in a hook-shaped extremity, 

 which is wanting in Amphipro'viverra, Cladosictis and Thylacynus. In 



FIG. 3. 



Thylacynus cynocephalus, pelvis and sacrum, x \. a, from the left side ; b, from above ; c, 

 from below. The epipubic cartilages are represented by the dotted outline. 



the latter genus the distal end of the humerus is much narrower trans- 

 versely than in either Prothylacynus or Cladosictis, and both supinator 

 ridge and inner epicondyle are smaller (cf. text fig. i, a and Pis. XLIX, 

 figs, i, ia, \b ; LV, figs. 2, 20). 



