344 
PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 
inner humeral epicondyle is perforated by a large foramen in Thylacynus, 
Prothylacynus and Cladosictis ; imperforate in A mphiprovivevva. In Pro- 
thylacynus, the supinator ridge terminates in a hook-shaped extremity, 
which is wanting in Amphiproviverra, Cladosictis and Thy lacy mis. In 
Fig. 3. 
Thylacynus cynocephalits , 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. 1, a and Pis. XLIX, 
figs. 1, la, ib; LV, figs. 2, 2a). 
