26 



DINOCERATA. 



The bony jialate is thus deeply excavated on each .side in the 

 region of the diastema, and near the jiosterior part of each excavation on 

 either side is situated a hirge foramen, which may be called the palato- 

 maxillary foramen. This foramen is shown in Plate V, and also in figures 

 22—24, b, page 25. The same foramen is seen, also, in the liippopotamus. 



%j^-::::^:f^:^^ 



FlGtTEE 26. — Skull of Dinoceras mirabik, Mnrsh (No. lO.TIJ); seen from helon-. 

 KieuKB 27. — Skull of Dinoceras laticeps, Marsh (No. lo:',!)); same view. 



a. anterior palatine foramen; J. palato-maxillary foramen ; c. antorbital foramen; (1 po.steiior paUitine 



foramen ; e. posterior nares ; /. foramen magnum ; f. occipital foramen ; g. stylomastoid foramen ; 



A. foramen lacermn posteriiis; i". vascular foramen in basisphenoul ; y. posterior opening of alisplienoid 



can.il ; k. anterior opening of alisplienoid caual; I. optic foramen. 



Both figures are one-eighth natural size. 



The palatine surface of the maxillary hone is perforated with small 

 foramina, along the line of the enclosed canal, as in the hippo})otamus, 

 evidently for the transmission of blood-vessels and nerves to tlie gums 

 and sm-face of tlie palate. 



