DEPARTMENT OF GEOLOGY 
29 
A skull of the primitive bear Amphicyon, skulls and skeletons 
of smaller carnivores, and skulls, feet and legs of three-toed 
horses considerably larger than appear in the preceding epoch. 
Also a mounted skeleton and series of skulls of Promerycochcerus, 
a successor to Ovcodofi of the last epoch; skulls of M etycochcBrus , 
Merychyus and other members of the Oreodont family, and 
skulls of Oxydactylus and Procamelus, members of the camel 
family. 
Another fossil from beds of this age shown is Dcemonelix, or 
Devil’s Corkscrew, a curious spiral form found in great abundance 
in the sandstone strata of western Nebraska. Its exact nature 
is problematical. Some think that it represents the remains of 
aquatic plants. According to another theory natural casts of 
ancient gopher burrows form the fossil. The series shown is 
thoroughly representative, and includes specimens of supposed 
stages of development of the form. (Alcove, Hall 60.) 
Other Tertiary forms represented include: 
Restoration of Colossochelys atlas, a huge turtle which lived 
in India during the Tertiary period. (Hall 60.) 
A restoration showing the jaws of Car char odon, and within 
these, for comparison, the jaws of a modem shark. The Car- 
char odon was probably 50 to 70 feet in length. (Hall 60.) 
A restoration of the skull of Elephas ganesa, one of seven 
species of elephants existing during the Miocene epoch in India. 
This species is remarkable for the length of its tusks, in this 
specimen ten feet long. (Hall 59.) 
Quaternary Period. — Vertebrate fossils of the Quaternary 
period are represented in the collection by remains of the masto- 
don, mammoth, bison, rhinoceros, Irish deer, New Zealand birds, 
cave bear, and cave man, as well as by a large series of casts and 
restorations. The largest of these is the skeleton of the masto- 
don from southern Michigan. This was one of the earliest ele- 
phant-like mammals, differing from the elephant in having a 
more elongated body, shorter and stronger limbs, flatter cran- 
ium and less complex molars. The grinding surfaces of the 
molars were more or less tubercular, in contrast to the ridges 
which characterize the teeth of the elephant. Hence comes the 
name, mastodon, nipple tooth. The animal probably had no 
hairy covering to enable it to endure a rigorous climate as did the 
mammoth. It inhabited chiefly the temperate regions of the Unit- 
ed States, where its remains are found in abundance. (Hall 59.) 
