PETERSON: A REVISION OF THE ENTELODONTIDA 59 
found in the upper Oligocene, it would seem quite reasonable to suppose that it 
belongs to the same species. 
The premolars of this skull are rather pointed, with wrinkled enamel, and with 
comparatively small antero-posterior diameter, approaching Dinohyus in these char- 
acters. P+ has asmall paracone and avery strong cingulum, which nearly surrounds 
the tooth ;. the external face is quite smooth, except the posterior and anterior angles. 
The molars have distinctly separated tubercles and rather broad or open cross-valleys. 
Opposite the cross-valley on the internal faces of M+ and M? the heavy rounded 
cingula, or swellings, which are so prominent in Dinohyus hollandi, are indicated. 
The anterior tubercles of M® are well separated, while the posterior tubercles are 
fused and elevated posteriorly, so as to form a basin of the cross-valley ; the tooth 
as a whole is relatively small when compared with Dinohyus. 
The frontals are much less inflated than in the typeof Dinohyus. Judging from 
the crushed condition of the skull, I am inclined to think that the anterior border of 
the orbit is opposite the posterior part of M%, or perhaps somewhat further back. 
The anterior border of the posterior nares is opposite the posterior part of M2. 
The dependent process of the jugal is very broad and extends well down. 
A second specimen in the Yale Museum, which may be referred to Pelonax 
bathrodon (No. 10009), is a skull and lower jaws of a rather young individual. This 
has an unusual development of the posterior basal tubercles (hypoconulids) of the 
lower molars. The ento- and hypoconids of My and Mz are also relatively high in 
comparison with most Entelodonts from the Oligocene, while those of Mz are low 
as in the type of Pelonaa bathrodon and the cross-valley is also broad in the same 
manner. 
MEASUREMENTS. 
Skull No. 10008, Yale Museum. 
Total length of the skull fragment about. 
Breadth of skull at M2 
Antero-posterior diameter of P2 
Transverse es 
“ ae 28 
Antero-posterior he 41.5 
“eo “ 831 
‘Transverse uf 834 
“e et 40 
Antero-posterior Ge 38 
i ie 89.5 
Transverse Ws 43 
ec oe 37 
Antero-posterior = 633 
