294 Prof. 0. C. Marsh— On Elotherium. 



YiG. 3. Discinocaris £rowniana, H.W. Modified by pressure. Moffat. Magnified 



2 diameters. 

 Fig. 4a, ib. Portions of two bodies or abdomens of, probably, D. Broivniana. On 



the same shale with Fig. 3. Magnified 3 diameters. 

 Fig. 5. Discinocaris Broivniana, H. W. Modified by pressure. Garpel Linn, 



Moffat. Magnified 2 diameters. 

 Fig. 6. Aptychopsis Wilsoni, H. W. Left-hand moiety of a carapace. Duff- 



Kinnel Burn, Moifat. Magnified 2 diameters. 

 Fig. 7. ElyniocarisIIindei,s^.ViOY. Magnified 1| diameters. Devonian; Arkona, 



Ontario, Canada. 



II. — Eestokation of Elotherium. 



By Prof. 0. C. Marsh, M.A., Ph.D., LL.D., F.G.S. ; 

 of Tale College, New Hayen, U.S. 



(PLATE X.) 



THE genus Elothernim, established by Pomel in 1847, represents 

 a family of extinct mammals, all of much interest. They 

 were first found in Europe, but now are known in the Miocene of 

 North America, not only on the Atlantic coast, but especially in the 

 ]^ocky Mountain region, and still further west. This family includes 

 several genera, or subgenera, and quite a number of species, some 

 of which contain individuals of large size, only surpassed in bulk 

 among their contemporaries by members of the Ehinoceros family, 

 and of the huge BrontoiJieridce. 



Eemains of this group have thus been known for nearly half a 

 century, yet, until recently, comparatively little had been determined 

 with certainty regarding the skeleton, or of the skull except the 

 dentition, although Aymard, Leidy, Kowalevsky, and others have 

 made interesting contributions to the subject. In a late paper ^ the 

 writer gave figures of a finely preserved skull, and also of a fore and 

 hind foot, of one of the largest species, Elotherium crassum, Marsh ; 

 and in the present article an attempt is made to restore the entire 

 skeleton of this animal, to serve as a typical example of the group. 



The restoration, one-twelfth natural size, given on Plate X., 

 represents a fully adult individual, which, when alive, was more 

 than seven feet in length and about four feet in height. The 

 basis of this restoration is the type specimen of Elotherium crassum, 

 which was found by the writer in 1870, in the Miocene beds of 

 North-Eastern Colorado, and described in 1873.^ A number of other 

 specimens since obtained in the same region, and still others from 

 essentially the same horizon in South Dakota, all evidently pertaining 

 to this species, were likewise used in the restoration. 



The type specimen, although incomplete, includes portions of the 

 skull, with various vertebrae and bones of the limbs and feet, and 

 these were sufficient to determine the general form and proportions 

 of the animal here restored. The additional specimens used are 

 mostly in good preservation, and some of them are almost as 

 perfect as in life. Hence, the skeleton, as represented in Plate X., 

 is believed to be correct in all its essential features. 



^ American Journal of Science, vol. xlvi. p. 408, pi. viii. November, 1893. 

 2 j^j^_ ^ol. V. p. 487, June, 1873. 



