alpai Mountains, Pine
Springs, and Prescott under the name _Sylvilagus nuttallii pinetis_.
Nelson (_op. cit._:Pl. X, fig. 2) figured one of these skulls from the
Hualpai Mountains as _S. n. pinetis_ and the cranial measurements (_op.
cit._:201) that he records for _S. nuttallii pinetis_ likewise are of
these same specimens of _Sylvilagus floridanus holzneri_. Nelson's
description (_op. cit._:207-210) seems to have been affected by the
erroneous (as we see the matter) inclusion of these specimens of _S. f.
holzneri_ in the materials identified by him as _Sylvilagus nuttallii
pinetis_.

The specimens so far mentioned from Arizona can be identified with ease.
The identification becomes difficult, however, when the holotype of _S.
f. holzneri_, from the Huachuca Mountains, is examined. The difficulty
results from the holotype having a barely detectable emargination in the
posterior border of the supraoccipital shield. In this respect the
holotype is intermediate between _S. f. holzneri_ (as known by specimens
from more western localities in Arizona) and _S. n. pinetis_ from the
White Mountains to the northward. As noted above, _S. f. holzneri_ has a
deep notch and _S. n. pinetis_ has none. This intermediacy of the
holotype supports the possibility, mentioned by Nelson (_op. cit._:200),
that intergradation occurs between _S. f. holzneri_ and _S. n. pinetis_.
Additional evidence, however, is against this possibility; the notch in
the supraoccipital is deeper in specimens (No. 66136, from Chiricahua
Mts., and No. 204364, from Ash Creek in Graham Mts.) from mountains
geographically intermediate between the Huachuca Mountains and the White
Mountains. Also, the holotype of _S. f. holzneri_ differs from _S. n.
pinetis_ and agrees with other specimens of _S. f. holzneri_ from
farther southwest in Arizona in the robustness of the posterior
extensions of the supraorbital processes and in the considerable degree
of fusion of the tips of these processes with the squamosals.
Additionally, the rostrum of the holotype is wide and deep as in other
specimens of _S. floridanus_ from more eastern localities and is unlike
the narrow and shallow rostrum of _S. n. pinetis_.

If intergradation occurs in Arizona between the species _Sylvilagus
floridanus_ and _Sylvilagus nuttallii_, as Nelson (_op. cit._:200)
intimated it might, the intergrades probably will be found along the
Tonto Rim or in the territory between the Blue Range and the Graham
M