688 The Smithsonian Institution 



and imperfect, the latter having been evidently subjected to 

 violence while imbedded in a soft mud. Of hoofed animals, 

 there were seven species of four genera, belonging to the 

 Booidea, or cud-chewing animals ; two species of one genus be- 

 longing to the Suoidea, or hog-like animals; one species of the 

 Solipedia, or solid-hoofed animals; and four species of three 

 genera belonging to the Perissodactyla, or uneven-toed animals. 



The first specimen described belonged to a peculiar genus 

 of ruminants which, among recent animals, is more nearly 

 allied to the musk-deer, and was hornless. The next is of 

 a remarkable genus of ungulata, representing a type which 

 occupies a position in the wide interval existing between 

 recent ruminants and the anomalous fossil animal called the 

 Anoplotherium. Another genus was called Oreodon, and con- 

 stituted one of the links necessary to fill up the very wide gap 

 between existing ruminants and an exceedingly aberrant 

 form of the same family now extinct. There were also two 

 remarkable species of rhinoceros, differing from any remains 

 of this animal found in other parts of the globe. 



Another fossil belonged to the feline family, about a fifth 

 smaller than the American panther, and is probably the most 

 ancient known genus of this animal. Hundreds of fossil 

 turtles were found in the " Bad Lands," belonging to the 

 genus Stylemys, of which five species are described. The 

 memoir occupies one hundred and twenty-six pages, and is 

 illustrated by twenty-four plates, one of which is a folio. 



In 1855 a third memoir by Doctor Leidy, on <( The Ex- 

 tinct Sloth Tribe of North America," was issued in the same 

 series. This work forms an interesting addition to our know- 

 ledge of the extinct gigantic sloth tribe of North America. 

 It comprises a description of remains of the genera Megal- 

 onyx, Mylodon, Megatherium, and of a new genus which he 

 called Ereptodon. 



