PETERSON : DESCRIPTION OF NEW RODENTS 181 
THE SKULL. 
The general outline of the skull, as has already been stated, is suggestive of the 
Mylagaulids. It has, however, a number of characters similar to those of Steneofiber 
fossor. There are important characters, which probably, when the superior grinders 
are known, will show still more important generic diversity from Stencofiber. The 
skull — minus the nasals and the cheek-teeth —is excellently preserved, and 
deserves a somewhat detailed description. 
The greatly expanded superior border of the premaxillaries indicates a broad 
rostrum, which in width exceeds that of the interorbital space, although not to the 
same degree as that which obtains in S. fossor. The nasals are comparatively 
broader than in Steneofiber fossor, but do not extend any farther posteriorly. About 
midway between the anterior and posterior ends, the nasals are broadest, then they 
gradually taper to a serrated, rounded point at the junction of the frontals. The 
fronto-premaxillary suture appears to be on a line with the posterior end of the 
nasals, as is the case in Steneofiber, Cynomys, and Aplodontia. Thus the nasals in 
Huhapsis are entirely supported laterally by the premaxillaries. 
The frontals are rather short and broad anteriorly, with a heavy rounded supra- 
orbital margin. The interorbital space is relatively as wide as that found in the 
family Geomyide. The posterior extension of the frontal is also somewhat similar 
to that in the latter family, with a slightly more pointed posterior process. ‘There 
are no postorbital processes on the frontals. 
The sutures in the posterior portion of the skull are not discernible, so that the 
forms of the separate bones of this region cannot be ascertained. The parietal is 
very wide, and necessarily short, on account of the forward slope of the occipital 
surface. The median line is indicated by low ridges, which nearly meet to form the 
low sagittal crest. The superior portion of the parietals have only a slight convexity 
from side to side, giving a broad and depressed appearance to the skull. The inter- 
parietal is not visible. The lambdoid crest, which takes its origin at the postero- 
external point (mastoid process) of the squamosal, is highly characteristic in this 
form. The extreme anterior slope of the occipital surface places the union of the 
lambdoid and sagittal crests forward one fourth of the total length of the skull. 
This forward slope is greater than in Ceratogaulus rhinocerus Matth. The latter has 
a slope of 30° from a vertical position (Bull. Amer. Mus., XVII., 1902, p. 293), 
while Huhapsis platyceps has a forward slope of about 55° from the posterior face of 
the occipital condyles to the top of the crest. The lambdoid crest is moderately 
high, but very sharp. The entire area of the occipital surface has a gentle con- 
vexity from the base of the condyles upward and outward to the top of the 
