4 



excavated and exostosed for the attachment of a trunk in LoxolopJwdon. 

 The lateral and occipital crests of the cranium, though different from 

 the enlarged sinuses of the diploe of Elephants, represent the external 

 walls of this structure, and furnish a hint as to its mode of origin, and 

 serve to ease the transition to Perissodactyles. 



The differences in the cranium are consequent upon its anterior elonga- 

 tion, the nasal bones and premaxillaries becoming thus much extended. 

 The lachrymal is perforated by a small lachrymal canal in Uintatherium, 

 according to Marsh, but excavated on the margin only in LoxolopJwdon. 

 It is neither in Elephas. There is a postglenoid process more largely 

 developed than in Proboscidia vera. Other differences of still less import- 

 ance are to be seen in the anterior position of the exterior nares, and 

 the presence of horns. 



The Pantodonta are represented by Bathmodon. With a structure of 

 the hinder limb "nearly resembling Eobasileus, we have more pronounced 

 relationships to the Perissodactyles. The scapula has the massive 

 apical acuminatiou of the Proboscidia vera, and there is no round ligament 

 of the femur in some of them. The astragalus has the same flattened 

 form seen in Uintatherium and is even less like that of the Perissodac- 

 'tyla. The type of molars and the long compressed canines are similar to 

 those of Loxolophodon. On the other hand, the cervical vertebrae are 

 rather longer, and there is a rudimental third trochanter of the femur. 



History, etc. I originally referred the Eobasileidw to the Proboscidia, 

 on account of the structure of the limbs, and subsequently stated a num- 

 ber of reasons for this conclusion at a meeting of the Academy Natural 

 Sciences of Philadelphia, held January 14th, 1873 (published January 

 16th). In' the present paper, numerous confirmatory characters are 

 added. The Bathmodontidce I have heretofore referred to the Perisso- 

 dactyla. 



Prof. Marsh, in describing a species of this group, TitanotJierium 

 f anceps (July, 1871), compares it with perissodactyle species, and in de- 

 scribing the tibia says, that it "at its proximal end, has the femoral sur- 

 faces contiguous, with no prominent elevation between them, resembling 

 in this respect some of the Proboscidea. " A few days before the publi- 

 cation of my conclusions, in a foot-note (July 22d, 1872), he altered the 

 name Titanotkerium to Mastodon, indicating that he had reached the 

 same opinion. Shortly after (Amer. Journ. Sci. Arts, Sept. 27th), he 

 altered his view, constructing a supposed new order " Dinocerata," for 

 their reception. 



As regards the name of the order here defined as including the three 

 suborders above mentioned, I have preferred using one already employed 

 to coining a new one. This is the better course also, if, as is not unlikely, 

 the distinctions on which it, as well as the oiher two orders repose, shall 

 be broken down by new discoveries in paleontology. 



