CREODONTA. 313 



Measurements. 



M. 

 Length between Pm. iv and condyle, inclusive 0520 



Length of posterior three molars 0170 



Length of tubercnlar-sectorial 0070 



Elevation of tubercular-seetorial 0070 



Depth of ramus at sectorial 0100 



From the Big-Horn River, Wyoming. 



DlDYMICTIS CURTIDENS Cope, 



Paleoutological Bulletin No. 34, p. 160, Feb. 20, 1882. Proceed. Amer. Philos. Soc, 1882, Dec. p. 160. 



Plate XXIV d; fig. 10. 



As in the case of D. massetericus the present species is represented by 

 a single fragmentary mandibular ramus. This supports a sectorial tooth 

 of the size and form of that of the B. protenus, and is thus much larger than 

 that of the species just named. This tooth is placed nearer to the base of 

 the coronoid process than is seen in any other species, and only leaves space 

 for a short tubercular tooth. This is lost from the specimen, but the alveolus 

 shows pretty clearly its small dimensions. The base of the fourth premolar 

 remains, and it is evident that this tooth was like that of D. protenus in form 

 and proportions. The base of the posterior marginal lobe is present. The 

 ramus is deeper and larger than in the D. massetericus. 



Measurements. 



M. 

 Length of bases of last three molars 0285 



Length of bases of fourth premolar 012O 



Length of bases of sectorial on base 012 



Width of bases in front 008 



Depth of ramus at sectorial 017 



Big Horn basin. J. L. Wortman. 



0XYJ^:NA Cope. 



Report on Vertebrate Fossils obtained by the Wheeler Survey in New Mexico, 1874, p. 11 (extracted 

 from Report of Lieut. Wheeler to Chief of Engineers). System. Cat. Vert. Eocene New Mexico, 

 1875, p. 9. Report U. S. Geog. Survs. W. of 100th Mer., p. 95. 



Dental formula: I. ^7;; C. — ; Pm. — ; M. — -. Two small median su- 

 sO 1 4 2 



perior incisors and a very large external one separated by a diastema 



from the canine. The latter is large, and is followed with little interval by 



the first premolar. The two last premolars and all the molars of the supe- 



