E. L. Troxell — Entelodonts in Marsh Collection. 383 



sagittal crest. This is the only specimen at hand which 

 has well marked supraorbital foramina; these lead into 

 channels forward. The frontals are narrow anteriorly. 

 The lachrymal occupies but a small part of the orbit ; it is 

 narrow and extends upward and forward, giving room 

 for the end of the malar, which is large and high on the 

 face ; in consequence the zygomatic arch begins on the 

 maxillary. The anterior border of the orbit is over the 

 middle of M 3 . 



The extremely heavy canines and incisors are large in 

 proportion to the massive skull. The third upper incisor 

 is actually broader at the root than the canine of the type 

 of A. clavus davits. This third incisor is recurved and 



Fig. 12. — Archceotherium marshi, sp. nov. Holotype. Cat. No. 12025. 

 Crown view of lower jaws. One-fifth nat. size. 



caniniform; it is triangular, with the posterior side 

 rounded and flattened. The canine from the heavy root 

 tapers rapidly and is not so strongly recurved. 



P 1 is merely rudimentary, is separated from the canine, 

 and is situated squarely in the maxillary. P 2 , separated 

 from P 1 by a diastema of 23 mm., is also very small, and 

 is directed forward at an angle. It is about 10 mm. from 

 P 3 , which begins the series of five functional teeth; P 3 is 

 wide posteriorly, its inner face almost flat ; the enamel is 

 smooth, with hardly a trace of cingulum or ridge. P 4 is 

 subtriangular, with the corners considerably rounded. 

 It has the usual notch in front of the deuterocone. The 

 antero-posterior dimension is longer than the transverse. 



M 1 is almost circular, but the base of the hypocone is 

 indented; the form seems to be peculiar to this specimen. 

 M 2 is subquadrate, but with all the corners rounded and 

 much wider anteriorly where the base of the paracone is 



