470 



SINCLAIR— ENTELODONTS FROM THE 



expansion and concave longitudinally, accentuated by crushing. Its 

 front margin, at the point of greatest expansion, is in line with the 

 posterior border of the orbit. 



Fig. 2. 



Fig. 3- 



Fig. 2. Archccotherium scotti sp. nov. Holotype, No. 10885. Anterior 

 mental process of the right side, seen from directly in front, one quarter the 

 natural size. 



Fig. 3. Archceotherium scotti sp. nov. Holotype, No. 10885. Right ante- 

 rior mental process from below, one quarter the natural size. To get the 

 proper orientation, the drawing should be held overhead in an inverted po- 

 sition and viewed from below. 



Fig. 4. Archceotherium ingens Leidy. Holotype. The front of the lower 

 jaw showing the dependent processes. Copied from Leidy's figure, one quar- 

 ter the natural size. 



2. The zygomatic arch is 46 mm. wide at its narrowest part and 

 the jugal process is very thin, and, while it extends to the front edge 

 'of the glenoid fossa, it takes no part therein and is not visible in 

 side view, but only from below, as shown by the deep shading in 



3. Pi seems to have been double-rooted, judging from extremely 

 slight indications of a median constriction across the alveolus, but it 

 would be equally permissible to assume that the roots were con- 

 joined, with merely a groove extending lengthwise between them. 

 The empty alveolus measures 28 x 19 mm. 



4. The anterior mental processes are very large and extremely 

 broad at the base, anteroposteriorly (Fig. 3), but vertically the neck 

 is only 20 mm. thick at the middle, thinning out to an edge front 

 and rear. Distally, the process swells out to an oval bulb 61 x 36 

 mm. in diameters and curves outward, backward and upward (in 

 part due to crushing). So far as can be determined from the figure 

 of A. ingens (Fig. 4), the corresponding structure seems to have 



