Januarv 19, 1899] 



NA TURE 



27: 



It was at first believed impossible to mount a stone or 

 fossilised skeleton free like a recent skeleton, and the 



I robusium, skeleton of one of the largest species, female. 

 Oligocene of South Dakota. 



These reliefs, however, have the disadvantage of 

 practically burying one side of the animal, and thu^ 

 rendering many parts both immovable 

 and difficult of access for purposes of 

 study. In other words, the exhibitiorv 

 purpose too far supersedes the purely 

 scientific and research purpose. An 

 entire departure was therefore made ir» 

 the skeletons of the swimming rhin- 

 oceros, Mctamynodon ,and of the great 

 Titanotherium, both from the Oligocene. 

 A word will be of interest in regard 

 to the discovery of these animals. The 

 first remains of the Metamynodon were 

 secured in 1892, namely, the skull and 

 jaws and the greater part of the skeleton- 

 A vigorous search in 1894 supplemented 

 these parts by a complete left hind foot 

 and an almost complete right fore foot. 

 Bones of this animal are e.xtremely rare,, 

 and the only pelvis which could be found 

 belonged to an individual of slightly- 

 smaller size. With these materials, how- 

 ever, a complete skeleton was made up,, 

 and it shows clearly the many wide 

 contrasts between this animal and the 

 true rhinoceros. The animal in life was- 

 over nine feet long, and about five feet 



first experiments upon a large 

 Creodont or primitive Carnivore, 

 Pa/riofelis, the bones were placed 

 in high relief upon a background 

 of matrix resembling the original 

 rock in which the specimen was 

 found. This method was also 

 adopted in the skeleton oi Acera- 

 theriuDi tridactylum (Fig. 1)1 which 

 happened to be very much crushed 

 laterally, and was therefore pecu- 

 liarly fitted for mounting in relief 

 The result, as shown in the photo- 

 graph, was highly successful. This 

 skeleton, which is entirely original 

 except the left fore limb, conveys 

 to the visitor the idea of having 

 been literally hewn out of the rock, 



and thus the two-fold impression of age and of fossilisation 

 is at once given. 



NO. 1525, VOL. 59] 



high, with habits rather like those of the 

 hippopotamus than rhinoceros. In the 

 same year, 1892, the fortunate discovery 

 was made of a magnificent Titano- 

 therium skeleton in South Dakota. The 

 skull was first found in a somewhat frag- 

 mentary condition, and then the neck, 

 entire trunk and fore limb, perfect evert 

 to the sesamoids, were excavated as far 

 back as the last lumbar vertebra and the 

 border of one ilium. At this point there 

 was a great disappointment — the party 

 encountered a sudden change in the 

 rock, and found that the sacrum, the 

 remainder of the hip and hind limbs had 

 been carried away by an erosion which 

 had probal)ly occurred at some time 

 after the original deposition of the entire 

 animal It required the work of two 

 parties during the season of 1894 to 

 secure the bones of the hind quarters- 

 of proper proportion belonging to the 

 same species. The mounting method 

 adopted, as fairly shown in the photo- 

 graph (Fig. 2) consists in carrying steel rods upon the inner 

 sides of the limbs and arches, to connect with a main rod 



Eocene of Wyoming, 



