Fig. 4. 



Skull of Onohippidmm munizi. (From the model in the Museum, 

 No. N. H. 17). pf. preorbital fossR; or depression. About \ nat. size. 



Fig. T). 



Skull of a small S. American Derr, Pudua jfudu (No. N. H. 17), to show the 

 preorbital fossa, or depression (pf.), which contains a gland. ^ nat. size. 



[ To face page'Jl. 



