Notes on Sciurus Fossor. 119 
This squirrel varies in abundance in the same locality in succeed- 
ing years without apparent cause. Some hunters think it is subject 
to epidemics, which is probable. Last March I picked up one dead 
that on skinning showed no wound. It was much congested, so 
that the veins all over the body were very distinct. It was in fair 
condition for the season, so its disease was not of long standing 
The seasonable variation of this species consists of the addition 
in winter of an ochraceous or cinnamon-rufous wash over the upper 
surface, principally over the shoulders, but often extending from the 
neck to the rump. In some winter specimens this wash is quite 
strong, but in others it is hardly appreciable. This difference in 
color is only in the next to the last annulation of the hairs of the 
upper surface. These annulations in summer are nearly pure white 
but in winter they become more or less rufous colored. The last, 
blackish annulation or tip, being short, does not much obscure the 
color of the lighter band below. 
A comparison of specimens from San Bernardino and San Diego 
counties with specimens from near San Francisco in the collection 
of the Academy of Sciences shows the southern squirrel to be in- 
termediate between the two forms found near San Francisco. I 
hardly know whether to refer the southern animal to Sczurus fossor 
or to Mr. Bryant's new sub-species xigvifes. It may even need 
separation sub-specifically from both, as it is certainly a little differ- 
ent in color from either. The southern animal is quite constant in 
color except the presence of the ochraceous wash on the dorsal sur- 
face of some in winter. 
I have not been able to consult Audubon and Bachman’s original 
description of Sciurus leporinus, which has been discredited by most 
later authors, but from Baird’s reference to it | am inclined to think 
that it was founded on a northern California individual having an 
unsually strong wash of ochraceous or chestnut on the upper sur- 
face, about the color that I should expect to see on winter speci- 
mens from, say, Humboldt. It is probable that /eporinus will 
ultimately be restored and /fossor of Peale be placed in the list ot 
synonyms. 
