241 



constitution of the nose of Sivatheriuni led its discoverer and describer, Dr. 

 Falconer, to attribute a like prehensile organ to that animal. The strength 

 and co-ossification of the nasals, together and with the frontals and maxilla- 

 ries, are also no doubt related with the unusual position of the horn-cores, just 

 as a similar condition of things in the rhinoceros is related with the support 

 of a horn on the nose. 



Megacerops color adensis is estimated to have approximated two-thirds the 

 size of the Sivatheriuni giganteum. 



Measurements from the fossil referred to Megacerops color adenitis are as 

 follows : 



Inches. Lines. 



Distance from the summit of one horn-core to the other 10 G 



Length of curve between the same two points 13 10 



Length of lateral nasal notch from end of nasals 4 



Distance from end of nasals to center of space between horn-cores 



Breadth of nasals 2| inches behind the end -1 3 



, Thickness of nasals where co-ossified 1 3 



Diameter of horn-cores 1\ inches from summit fore and aft L! 10 



Diameter of horn-cores 2£ inches from summit transversely 2 5 



Breadth of face below horn-cores 8 8 



Breadth at bottom of lateral nasal notches 5 



• 



Since writing the above, I have recalled to mind a specimen of a horn-core 

 which was obtained by Dr. John Evans from the Mauvaises Terres of White 

 River, Dakota, and which is noticed in the account of Titanotheriuni, on page 

 216 of the " Extinct Mammalian Fauna of Dakota and Nebraska." The ref- 

 erence of the specimen to any particular animal was considered very uncer- 

 tain, though it was suspected that it might pertain to Titanotheriuni. It is 

 now represented in Fig. 3, Plate XXVIII, and is seen by comparison to bear 

 a near resemblance to the horn-cores of Megacerops. It is rather larger and 

 slightly more tapering and curved than in the latter; The specimen may, 

 perhaps, belong to another species of Megacerops. 



Since the foregoing was written, Professors Marsh and Cope have reported 

 the discovery of remains of several huge mammals in the Bridger Tertiary 

 beds, which they have described under the names of Tinoceras, Dinoceras, 

 Fobasileus and Loxolophodon. The ordinal relations of these is a matter of 

 dispute, and it is a question especially whether they are proboscideans, or are 

 representatives of a previously unknown order. One of their most remarkable 

 peculiarities is the possession of several pairs of bony protuberances to the 

 skull, which are viewed as horn-cores. 

 31 G 



