Revieics — Prof. 0. C. Harsh' s Binocerata. 



221 



The Brain. — " The brain of the Dinocerata is one of the most 

 peculiar features of the group. It is especially remarkable for its 

 diminutive size. It was proportionately smaller than in any other 

 known mammal, recent or fossil, and even less than in some reptiles. 

 It was, indeed, the most reptilian brain in any known mammal. 

 In Dinoceras mirabile, the entire brain was actually so diminutive 

 that it could apparently have been drawn through the neural canal 



Fig. 10. — ^View of the upper surf ace of skull Fig. 11. — View of the upper 



of Tinoceras ingens. Marsh ; one-eighth nat. surface of the skull of Dinoceras 



size, with brain-cast in position. /, frontal laticeps, Marsh, (female) with the 



bone ; m, maxillary bone ; m, maxillary pro- brain-cast in position. One- 



tuberance ; n, nasal bone ; n', nasal protu- eighth the natural size. 

 berance ; p, parietal bone ; p', parietal pro- 

 tuberance ; pm, premaxillary bone. 



of all the prsesacral vertebrae, certainly through the cervicals and the 

 lumbar ones. 



" The size of the entire brain, as compared with that of the 

 cranium, is shown in the accompanying Figures, 4, 5, and II. The 



