238 ON THE EXTINCT MAMMALIA OF 



Its breadth is a little over two inches, and its length or fore and aft measurement at 

 the sides is about the same extent. In the median line it is little over an inch fore 

 and aft, and its depth is twenty-two lines. 



Several distal ends of humeri resemble the corresponding parts in the Indian 

 Rhinoceros, but have the process on the outer condyle pi-ojaortionately less well-de- 

 veloj)ed. They measure about two and a half inches in width, with the articular 

 surface an inch and three-fourths wide. 



The proximal ends of a radius and ulna are like those of the Indian Rliinoceros. 

 The breadth of the fore-arm bones together on a level with the head of the radius is 

 two and a quarter inches. 



The distal extremity of a femur is three and a quarter inches in breadth, with the 

 articular surface of the condyles two and three-quarter inches wide, and that of the 

 trochlea an inch and a half wide. 



An entire tibia, in Dr. Owen's collection, has the same form as that of the Indian 

 Rhinoceros. Its length is eleven and a half inches ; the width of the head three and 

 one-third inches, and of the distal end two and one-sixth inches. 



Among a collection of fossils obtained in Colorado Territory by Dr. E. T. Berthoud, 

 recently sent to me by the Smithsonian Institution for examination, there are frag- 

 ments of two lower jaws, apparently of Hyracodon nehrasce')isis, labelled " Currant 

 Creek, West Fork, lat. 40° 55', long. 109° 34'." Li one of the specimens, containing 

 the fangs of the last three molars, the series occupied a space of thirty-four lines, and 

 the depth of the jaw at the middle of the last tooth is twenty-one lines. The other 

 specimen, containing the last two molars and portions of the two in advance, has the 

 series of the last three occuj)ying a space of twenty-nine lines, indicating a smaller 

 individual than the former. 



TAPIRID^. 



The family of the Tapirs is represented in the miocene deposit of the Mauvaises 

 Terres of Dakota by a species of Lophiodon, an extinct genus characterized by Cuvier 

 from remains of several species found in formations of the same age in Europe. The 

 only specimen, though a perfectly characteristic one, indicating the former existence 

 of an American Lophiodon, consists of a single tooth, discovered by Dr. Hayden and 

 attributed by him to the Titanotherium bed, or bed A, of his section of the tertiary 

 deposits of Dakota. 



