62 



DAPHiENUS EBLINUS, ScOtt. 



Plate VII, figs. 15 and 16. 



Daphcenus felinus, Scott, 1898. Notes on the Canidse of the White River Oligocene; 

 Trans. Amer. Philos. Soc, vol. XIX, p. 361. 

 The hinder part of a right maxilla, in which is preserved the sectorial tooth, is referred 

 to this species with a certain amount of doubt. The specimen includes the alveoli of the 

 third premolar and of the three molars. 



In his " OUgocene Canidse," Hatcher* has made known the complete dentition of this 

 species, from excellent material from the Oreodon beds of Bad Lands creek, Sioux county, 

 lifebraska. In comparing the dentition of the Cypress Hills specimen, so far as its incom- 

 pleteness will admit, with that of the species as set forth by Hatcher in his description and 

 figures (plates XIV and XVI) it is seen that there is a fair agreement in the size of the 

 sectorial (fourth premolar), and the space occupied by the teeth from the third premolar to 

 the second molar, both inclusive, is almost the same, giving about a corresponding size to the 

 third premolar,and the first and second molar teeth. A difference is noted in the position of the 

 alveolus of the third molar, which is placed farther outward in the Canadian specimen, being 

 in line rather with the exterior borders of the first and second molars than with the inner 

 margins of the same as shown by Hatcher. The alveolus of the third molar is very close 

 to the hinder border of the second molar, and indicates a greater crowding of these teeth, 

 with a probably smaller antero-posterior diameter to the second molar. There seems also to 

 have been a greater backward obliquity to the outer border of the second molar. In the 

 sectorial tooth of the Cypress Hills specimen the antero-internal cusp (deuterocone) is longer 

 and narrower, and is directed more forward, so as to form with the base of the external cone 

 a decided fork, into which the posterior border of the third premolar fitted closely. The 

 deuterocone has a slightly convex upper surface (within the ciDgulum),on which is developed 

 a distinct longitudinal median ridge. The antero-external cone (protocone) and the posterior 

 cone (tritocone) apparently agree well with the corresponding parts of the sectorial of the 

 Nebraska skull. A basal cingulum is present; it is moderately developed internally, and 

 includes the anterior border of the deuterocone, but is rather weak externally. 



Hatcher (op. cit., p. 67) has drawn attention to the difference in the position of the upper 

 third molar relative to the two preceding molars in the genera Amphicyon and Daphcenus, 

 His remarks appeared as follows : — " The chief generic distinctions between Daphcenus, Leidy, 

 and Amphicyon, Lartet, in so far as they are at present known, are to be found in the relative 

 size of the premolars, structure of canines, and position of the superior third tubercular molar. 

 The canines of Daphcenus are without either anterior or posterior cutting; edges, while these 

 are present in Amphicyon. The premolars are reduced in size in Amphicyon, while those of 

 Daphcenus show little or no reduction. In Daphcenus the superior third tubercular molar is 

 pushed inward and aligned with the internal cones of the preceding molars, while in 

 Amphicyon this tooth occupies a more external position." 



In the Cypress Hills specimen (1) the canine is not preserved, so that a comparison cannot 

 be made in this connexion, (2) the fourth premolar at least is not reduced in size {Daphcenus} 

 and (3) the third molar is in line with the external cones of the preceding molar {Amphicyon), 



'Memoirs of the Carnegie Museum, Pittsburgh, vol. I, No. 2, Sept., 1902. 



