472 SINCLAIR— ENTELODONTS FROM THE 



which the supporting framework of the mounted skeleton now inter- 

 feres. P4 has its outer and back sides square, the inner rounded 

 and the front deeply indented. On the anterior outer corner a 

 prominence rises from the cingulum and the latter is present front 

 and rear. Molars one and two are quadrangular, but too worn to 

 show the crown patterns. Heavy cingula are present front and 

 rear. In m3 the crown narrows in width posteriorly, the outer wall 

 of the tooth converges inward, and there is a small posterior cin- 

 gulum. 



In the lower series incisors and canines are represented by empty 

 alveoli, as is also pi, which, as indicated above, may have been either 

 double-rooted or with a single grooved root. It is 14 mm. back of 

 the canine and 16 mm. from the base of p2. The latter is a double- 

 rooted tooth without cutting edges in its present worn condition. 

 The back of the crown is broken, so I can not determine whether it 

 is of uniform width throughout. P3 is long anteroposteriorly (52 

 mm. on alveolar border) in proportion to its width (20 mm.). The 

 worn crown is convex on both sides and there are no cutting edges. 

 There is a slight basal tubercle in front and a long sloping shelf 

 behind, the worn area extending down over the posterior root below 

 the enamel. The remaining teeth are in close series. P4 is heavier 

 and thicker than the preceding and wider in front than behind. 

 The sides are plane and there are no cutting edges on the worn 

 crown which measures 39 by 22 mm. The molars are well worn, 

 but retain traces of cingula front and rear. The anterior cusps 

 seemingly were higher than the posterior. M3 has a prominent 

 hypoconulid and the tooth crown is a little wider anteriorly than 

 posteriorly. The other molars are of uniform transverse width. 



II. From the Oreodon Beds. 

 ArchcE other 'mm wanlessi sp. nov. 



Type No. 12522, Princeton University Geological Museum, col- 

 lecting locality ioi5A2a, a splendid uncrushed skull with attached 

 lower jaw and the first to fourth cervical vertebrae (Figs. 5, 6, 21) 

 found by Mr. H. R, Wanless of the 1920 South Dakota Expedition 

 on the 14th of last July in a large rusty nodule weathered out of the 



