241 



constitution of the nose ot SivHtlieriiuu led ils (li.scoverei- and descriher, Dr. 

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

 and co-ossitication of the nasals, together and with the frontals and niaxilla- 

 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 Iiorn on the nose. 



^[(gacerops coloradcnsis is estimated to have approximated two-thirds the 

 size ot the Sivatherium g'lganteum. 



Measurements from the fossil referred to Mpgacerops coloradenus are as 

 follows : 



luches. Liues. 



Distauce from the summit ot oue horucore to tbe otlicr ' 10 



Length of curve between the same two poiuts I'j 10 



Length of Literal nasal notch from end of nasals 1 



Distauce from end of nasals to center of space between liorncores 



Breadth of nasals 2^ inches behind the end 4 o 



Thickness of nasals where co-ossifiod ... « 1 3 



Diameter of born-cores 2i inches from summit fore and aft 2 10 



Diameter of horn-cores 2^ inches from saiiuuit transversely 2 5 



Breadth of face below born-cores 8 8 



Breadth at bottom of lateral nasal notches 5 6 



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 AVhite 

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

 216 of the " Extinct Mammalian Fauna of Dakota and Neliraska," The ref- 

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

 tain, though it was suspected that it might pertain to Titanotherium. 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 Coi)c have repoiied 

 the discovery of i-emains of several huge nuimmals in the Bridger Tertiary 

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

 Eobasileus 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 

 pecuharities is the possession of several pairs of bony jirotuberances to the 

 skull, which are viewed as horn-cores. 

 31 G 



