480 



SINCLAIR— ENTELODONTS FROM THE 



MEASUREMENTS. 



A. wanlessi. 



A. crassum. 



A.mor- 

 toni. 



No. 

 I 1440. 



Length of symphysis. _. 



Depth of jaw below pi 



P2_- 



" " " " m2 



' ni3 



Narrowest part behind anterior mental tubercles, 



ventral 



Narrowest part anterior to mental tubercles . . . . 



Anterior mental tubercles, lateral extent 



The same for posterior mental tubercles 



Space occupied by lower pms. and ms 



Lower premolar length 



Lower molar length 



P4, anteroposterior diameter 



M2, transverse diameter 



M2, anteroposterior diameter 



mm. 

 97 

 55 



SI 

 51 

 56.S 



35 



46 



72 

 103 

 196 

 128.5 



70 



25-5 



16.5 



24 



III. From the Protoceras Beds. 

 Scaptohyus altidens gen. et sp. nov. 



Type No. 11 161, Princeton University Geological Museum, front 

 of skull, lower jaws, left cheek flange and minor fragments from 

 the Protoceras beds in Corral Draw, South Dakota, collected by 

 R. E. Zuver, cook of the 1893 Expedition. 



This remarkable entelodont has figured several times in the litera- 

 ture because of the striking way in which it demonstrates the dig- 

 ging habits of the animal. I have long been aware that the speci- 

 men represented an undescribed form, and now propose it as the 

 type of a new genus Scaptohyus ("digging pig") and species alti- 

 dens in reference to the great height of the third lower premolar 

 (Figs. 11-17). With Professor Scott's kind permission, I repro- 

 duce from " A History of Land Mammals in the Western Hemi- 

 sphere," Macmillan Company, his Fig. 194, with certain corrections 

 which I fear detract from the artistic quality of Mr. Horsfall's 

 drawing, but express more accurately the structures present (Fig. 

 13). In reference to them, Professor Scott writes "the external, 

 or third, upper incisor tooth has a deep, triangular notch worn in its 



