294 



DAVIDSON BLACK 



Cerebellum. On the cerebellar portion of the cast somewhat 

 more of detail has been preserved than in Specimen IV. The 

 tentorial groove is here quite sharply marked and the irregulari- 

 ties of the endocranial surface due to the parieto-occipital and 

 associated venous channels are not very prominent. In all essen- 

 tials the cerebellar morphology, as evidenced by the surface 

 markings of the cast, corresponds with that of Specimen II 

 described above. In view of these facts as well as on account of 



R. s. p,. 



^.lat. 



Ra.eci. 



For, con. 'M.a.i. 



For. ov. 



19 



'Frhin. a. 



P.a.ect. R-W^P^sf 



-R.d.s. 



^.lat. 



For. lac. ant For.ov. -For. lac. post. for. con. 



20 



Figs. 19, 20, 21 and 22 Camera lucida drawings of natural endocranial cast of 

 Oreodon, Specimen V, right lateral, left lateral, dorsal and ventral views re- 

 spectively. For photographs see figures 45 to 48. Abbreviations: F.rhin.a.. 

 anterior rhinal fissure; S. pseud., pseudosylvian notch. Other abbreviations as 

 before. 



