282 THE PFERCO FAUNA. 



Deltatherium BALinviNi Cope. 



Proceedings American Pliilosopkical Society, 1882, p. 463 (Nov.) 

 Plate XXIII .1; lig. IS. 



'Hiis Creodont is known only from a portion of a right mandibular ramus, 

 which supports the two last premolars and the first true molar, with part of 

 the second. It differs from the D. fundaminis in its materially smaller size, 

 and in the forms of the teeth. The first true molar is a more robust tooth, 

 and the basis of the posterior or heel crest is more rounded and less angu- 

 late. The anterior inner cusp projects less anteriorly. The fourth pre- 

 molar has a distinct anterior basal lobe, which is wanting in the D. funda- 

 minis. Its heel is short and wide, and the posterior face of the principal 

 cusp is flat, and there is a rudiment of an internal tubercle on its side. 

 The second premolar is elevated and acute, has no anterior basal lobe, and 

 has a very short, wide heel. Enamel slightly roughened. The animal was 

 rather aged. 



Measurements. 



M. 

 Length of Pni. ii and iii and M. i 0160 



Diameters M.i^'"'t'''-"P''«t''"°^ ^'=^ 



< transverse 0040 



Elevation of crown of Pin. iii 0052 



Depth of mandible at M. i 0180 



From the Puerco beds of Northwestern New Mexico. Dedicated to 

 Mr. D. Baldwin, the discoverer of the niannnals and fauna of the Puerco 

 beds, which is one of the most important in the history of American paleon- 

 tology. 



Deltatherium lnterruptum Cope. 



Proceed. Anier. Philos. Soc, 1882, p. 463. 

 Plate XXIII d; fig. 13. 



The smallest species of Ddtathcrimn is, like the D. hdldwini, only rep- 

 resented by the anterior part of a right mandibular ramus, which suppoits 

 the last premolar and the first true molar, with tlie bases of the other pre- 

 molars and part of the canine. The canine is small, and the first premolar, 

 in accordance with the generic character, is wanting. The second premo- 

 lar is two-rooted. The fourth has an elevated principal cusp and a narrow 



