8 Myron Harmon Swenk 
occipital crests are not very great, dnote slightly stronger in E. 
e. epixanthum. 
Compared with the description of the skulls of ¢ and 9 E. e. 
nigrescens, brunert apparently differs, as from FE. e. epixanthum, 
in the poorly developed fronto-parietal depression and lateral © 
border of the interorbital region. In these respects the skull of 
E. e. bruneri agrees with that of E. e. myops, as well as in the 
poorly developed sagittal and occipital crests; but the skull is 
longer and the nasals are more narrowed posteriorly than in 
myops, while the brain case does not narrow posteriorly but rather 
broadens, and the form of the zygoma and the outer wall of the 
antorbital vacuity are not as described for myops but as these 
occur in epixanthum. The skull of E. e. bruneri is much larger 
than that of the subadult type of E. e. couesi, and the audital 
bullae are as large or even larger than in that form, but the form 
of the nasals is apparently much the same. In the figures given 
by Baird® of a paratype of FE. e. couesi (Bill Williams Fork, 
Arizona, 1854, C. B. R. Kennerly: U.S: N> M., 1262) the masals 
resemble those of typical epixanthum J and the audital bullae are 
no more inflated than in epivanthum,; possibly this specimen 
really represents epixanthum and not couesi. 
The skull of £. e. bruneri 9 compared with an adult 9 skull of 
E. dorsatum:dorsatum from Wisconsin (Field Mus. Nat. Hist., 
16284.) reveals considerable similarity, the nasals in both forms 
narrowing posteriad from the anterior extremity, but these bones 
are throughout broader and proportionately longer in bruneri, 
more than one-third of the total length of the skull, while in EZ. 
dorsatum they are less than one-third of the total length of the 
skull. These differences are even more accentuated between 
typical epiwanthum and dorsatum, but less so between myops and 
dorsatum. The form of the outer wall of the antorbital vacuity 
in dorsatum also resembles that described for myops rather than 
that of epixanthum, couesi or bruneri. 
These cranial differences may be expressed concretely by the 
following table of typical measurements: 
9 Mammals of North America, plate LV, fig. 1, a, b, c, d and e. 
LAA 
