CREODONTA. 277 



The first inferior true molar has a strong external cingulum ; the second 



has none ; the third has one, which is most evident between the cusps, is 



weaker at the base of the posterior lobe, and faint at the anterior lobe. No 



internal cingula. 



Measurements. 



M. 



Length of true molar series 052 



Length from M. iii to anterior masseteric ridge 013 



Diameters of M-i^^^t^'"?"*^*""' l]], 



I transverse Olio 



T^. . - ■,, ..(anteroposterior 018 



Diameters of M. u < ' ., , 



< transverse Oil 



Diameters of M. iii 5 *'^**^°P°«*«"'"' • *'^*^ 



( transverse 0105 



Depth of ramus at M. iii 047 



Width of ramus at M. iii inferiorly 013 



The molar teeth of this species are more like those of the T. heilprin- 

 ianus than those of the T. quivirensis. This is seen in the more conic char- 

 acter of the anterior lobe of the tooth, and the better development of the 

 anterior inner cusp. The species is a good deal larger than the T. quivirensis. 



From the Puerco beds of N. W. New Mexico, D. Baldwin. 



DELTATHERIUM Cope. 



American Naturalist, 1881, March 25, p. 337, Lipodectes Cope, 1. c, 18S1, p. 101-9. 



Dental formula : I. ^; C. p Pm. p M. |-. 



Superior premolars, the first and second with simple crowns, the third 

 with one large external cusp and an internal small one. The fourth 

 premolar with a large, simple external cusp and a prominent internal 

 one. The first and second true molars with triangular bases, supporting two 

 external compressed conic cusps and a subtriangular internal one. Last 

 molar similar in its internal portions, the external part narrow. A wide 

 diastema in the lower jaw. Inferior premolars simple, two rooted. True 

 molars with anterior inner cusj) well developed, forming with the anterior 

 external a sectional edge, as in Stypoloi^lms. Heels well developed, much 

 produced, and supporting a special tubercle in the last molar. 



The superior molars of this genus may be distinguished from those of 

 Pelycodus by the absence of the intermediate tubercle and of the posterior 

 internal tubercle. They differ from tliose of Esthonyx in the absence or 



