E. L. Troxell — Entelodonts in Marsh Collection. 439 



posed. The front and outer sides are straight, while the 

 other two form a regular curve. The cingulum in front 

 does not extend on to the corners strongly. The hypo- 

 cone is a small double cusp, but the protoconule is strong; 

 the paracone and metacone are equal, but the base of the 

 latter is large. 



The things of particular interest in the lower jaws (fig. 

 18), are the great slenderness of the branches and 

 the great width of the molars compared to their length. 

 Unfortunately the tubercles are broken away and the chin 

 is crushed, but the great width across the alveoli of the 

 canines and the flatness of the chin imply rather large 

 tubercles. The processes midway on the rami are below 

 a point between P 4 and M t ; the bases are oval in cross- 

 section and the tubercles probably hung down as well as 



Fig. 18. — Megachoerus latidens, sp. nov. Holotype. Cat. No. 10009. 

 Crown view of lower jaw. Dotted lines show permanent canines appearing. 

 One-fifth nat. size. G ly permanent canine; P 3 and Dp 3 , permanent and 

 deciduous third premolars; P 4 , fourth premolar; M 1? first molar. Ent, 

 entoconid; HI, hypoconulid; Hy, hypoeonid; Me, metaconid; Pr, pro- 

 toconid. 



outward. They were thin and not very extensive along 

 the borders of the rami. 



The symphysis is very short but the groove above is 

 shallow and widely open. The coronoid process rises out- 

 side the line of the molars, is thin, especially posteriorly, 

 and is approached closely by the masseteric fossa; this 

 depression is not extensive vertically and does not have an 

 abrupt margin. 



The permanent canines are just coming in and the tips 

 are barely visible (dotted lines, fig. 18). The first decid- 

 uous premolar is only 10 mm. behind its canine ; it is 25 

 mm. in front of Dp 2 . Dp 3 is very long but narrow; be- 

 neath it can be seen the tip of P 3 , the characters of which 

 are not known. 



