358 GEOLOGICAL SURVEY OF THE TERRITORIES.. 



LOPHIOTHEEIUM. 



An extinct genus of this name, described by Professor Gervais, from 

 remains found in the eocene formation of France, appears also to have 

 been represented by a small species during the formation of the Bridger 

 Group of tertiary deposits. 



Lojyliiotherium sylvaticum. — The species is indicated by a jaw frag- 

 ment with teeth, obtained during Professor Hayden's last expedition on 

 Henry's Fork of Green River, Wyoming. The animal was about two- 

 thirds the size of the collared peccary. 



Proboscidece. 



Of all extinct animals none are more familiar to the community than 

 the great proboscideans. Their huge bones, strewed over the earth, 

 have excited the attention of the least observant, and in former years 

 were viewed as unmistakable evidences of the earlier existence of a 

 race of giant men. Even now, to the uninformed their remains have 

 not ceased to be objects of wonder and the most convincing proofs that 

 informer ages huge animals roamed over the country where now they 

 no longer exist. 



MASTODON. 



This extinct genus of elephants appears to have once lived throughout 

 the greater part of the world. A half dozen species inhabited Europe, 

 the same number Asia, two South America, aud at least three, if not 

 four or five, North America. 



Mastodon americanus. — The great American mastodon appears to 

 have extended throughout the whole of North America during the 

 quaternary period. Its remains are among the most abundant of fossils 

 and have been found in almost every state and territory of the United 

 States. Complete skeletons, together with skulls of others, in a* fine 

 state of preservation, are among the most conspicuous and striking 

 objects of several of our museums. It is probable that this species 

 still continued to exist at the time of man's appearance on the stage 

 of life. 



Mastodon mirificus. — This species, whose remains were first discov- 

 ered by Professor Hayden, on the Loup Fork of the Niobrara Eiver, 

 lived at an earlier period than the preceding, pertaining, as supposed, 

 to the pliocene age. It was about the size of the common mastodon. 



Mastodon Shepardi. — A third species, probably of miocene age, has 

 been recently characterized from a fragment of a tusk, from Stanislaus 

 County, California. The tusk ot the common American mastodon is 

 composed alone of ivory, as in the modern elephants ; but the fragment 

 just alluded to presents a broad baud of enamel, as in the tusks of the 

 narrow-toothed mastodon of the miocene formation of Europe. The 

 species is named in honor of Professor C. U. Shepard, of Amherst Col- 

 lege, by whom the fossil was submitted to the writer. 



Mastodon obscurus. — This name has been appropriated to a supposed 

 species, founded on a tooth which was reported to have been discovered 

 in the miocene deposit of Maryland. Fragments of similar teeth from 

 North Carolina and Georgia appear to confirm the distinctness of this 

 species from M. americanus and M. mirificus. A portion of a lower jaw 

 containing a last molar, like the Maryland tooth, was recently discov- 

 ered in Contra Costa County, California. This specimen also clearly 



