366 XOTES ON THE CAjSttD^E OF THE WHITE RIVER OLIGOCENE. 



/IMS. It is composed of the same elements as m A., but has a different shape, owing to 

 the greater proportionate length, antero-posteriorly, of the inner portion of the crown. 

 In appearance this tooth is a miniature copy of that of Canis. 



B. Lower Jaw. — The incisors are very small and closely crowded together, so that 

 the fang of i % is pushed back out of line with the other two. 



The canine, which is even more compressed laterally than the upper one, is long and 

 recurved ; it is separated from p j by a very short diastema. 



The first premolar is a very small, simple cone, inserted by a single fang. The sec- 

 ond is much larger and is supported by two roots ; it has an anterior basal cusp, which 

 is formed by the cingulum and is subject to considerable variation, being much larger in 

 some individuals than in others. The third premolar has a high, compressed and sharp- 

 pointed crown and bears three accessory cusps, anterior and posterior basal cusps formed 

 by the cingulum, and a third developed upon the posterior edge of the protoconid, very 

 much as in Canis. The fourth premolar is slightly larger than p 3 and has more dis- 

 tinctly developed accessory cusps, but ou both p 3 and p 4 these cusps are subject to much 

 variation and in some specimens they are feebly marked or even absent. 



The European C. intermedius has very similar premolars to those of C. gregarius, 

 and in both species the anterior basal cusps (which are not present in Dapjuenus) give a 

 somewhat viverrine character to the dentition. 



The first molar has a quite elevated anterior triangle, with a high, pointed proto- 

 conid and a well-developed paraconid, both of which are more compressed and trenchant 

 than in Daphcenus. The metaconid is smaller than in the latter and is placed lower 

 down and more posteriorly, so that it is visible from the outer side, much as in the mod- 

 ern dogs. The heel is basin-shaped and is composed of a large, crescentic external cusp 

 and a smaller internal cusp. In the European species may be observed certain differ- 

 ences in the structure of the lower sectorial from the White River form, though these 

 differences are not great. Iu the Old World species tin- anterior triangle is higher and 

 the protoconid less compressed, while the metaconid is larger and occupies a more ele- 

 vated and anterior position: in other words, the anterior triangle resembles that of 

 Daphcenus. Another difference from the American forms consists in the presence of a 

 second internal cusp in the heel of the sectorial, which may be observed in most of the 

 individuals figured by Schlosser and Filhol. However, in a specimen of C. lacustris from 

 Debruges, which the Princeton Museum owes to the courtesy of Prof. Gaudry, this sec- 

 ond cusp is not visible. In perfectly unworn teeth of Daphcenus harlshornianus a feeble 

 indication of this second cusp may be seen. 



The second molar is tubercular and of a narrow and elongate oval shape ; in consti- 

 tution it entirely resembles that of Canis; the paraconid has disappeared, while in 



