J. B. Hatcher — Recent and Fossil Tapirs. 175 



all the skulls I have been able to examine and in the published 

 figures of them. The nasals are long, broad posteriorly, narrow 

 anteriorly and separated throughout their entire length, near 

 their base there is a deep excavation for the lodgment of the 

 cartilaginous air sinus. Sup. pm. 1 is longer than broad, the 

 internal cone is placed farther forward than in T roulini. 

 The cross-crests in sup. pm. 2 are not complete in the present 

 specimen, but I notice that in other specimens they are quite 

 complete. 



Elasmognathus Gill.* 



This genus has not been generally accepted, but the charac- 

 ters assigned to it by Dr. Gill are constant and seem to be of 

 generic importance. In addition to the characters already 

 pointed out. I may mention the extreme breadth of the top 

 of the skull which may almost be described as without a 

 sagittal crest, and the invariably complete molariform condition 

 of sup. pm. 2. Species of the present genus rival in size 

 T. indicus, the largest of the species of Tapir us, and include 

 the most specialized forms belonging to the Tapiridae. 



Elasmognathus bairdii Gill.f 



The principal characters of the skull and sup. dentition of 

 this species are shown in figs. 4, plate Y, and 4 and 4a, plate 

 IV, drawn from No. 515 in the Yale Coll. The ascending 

 posterior arm of the maxillaries, which articulate with the 

 lachrymals and frontals is much compressed and entirely con- 

 cealed by the latter bones, when the skull is viewed from the 

 side. The premaxillary is short and obtusely pointed, posteri- 

 orly. The post-tympanic and postglenoid processes approach 

 each other inferiorly but do not meet. The nasals are longer 

 than broad, are closely applied throughout their entire length 

 and coossified in old individuals ; they usually ossify, each, 

 from a single center, and posteriorly, they are but little sepa- 

 rated by the anterior median prolongation of the frontals. 



Elasmognathus doioi Gill.J 



In general, the skull and dentition of the present species 

 resembles so closely those of the preceding that it is not neces- 

 sary to figure the latter. Alston § has shown that most of the 

 specific characters ascribed to E. dowi are quite variable, and 

 hardly of specific importance. He says on page 98 of the work 



* See Proc. Phil. Acad. Sci., 1865, p. 183. 



f See Proc. Phil. Acad. Sci., 1865, p. 183. 



% See this Journal, 18*70, p. 142. 



§ See Biologia Centrali- Americana, Mammalia by Edward R.Alston, 1879-1882. 



