686 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
renamed the same form bedcheri in 1842, and Baird, in 1855, distinguished 
Sciurus suckleyi, which two years later, after the reception of additional 
specimens, he himself referred to douglassi. The S. lanuginosus of Bach- 
man is based on a white-bellied, light-colored specimen, said by Townsend 
to have been collected at Sitka. It agrees very well with the light-colored; 
white-bellied phase of dowglassi from Fort Crook, Cal, and I have little 
doubt is referable to dowglossi. Professor Baird, however, regarded it, after 
an examination of the specimen, as an albinistic example of S. richardsoni, 
admitting, however, that it is possibly referable to dowglass?, which view the 
locality, if correctly stated, certainly favors. To this variety is also refera- 
ble the S. mollipilosus of Audubon and Bachman, based on a specimen from 
the “northern parts of California”, in which the lower parts were cinereous, 
slightly tinged in places with rufous. 
The form next specifically distinguished was the S. richardsont of Bach- 
man, based on a small specimen from the “high range of the Rocky Mount- 
ains, west of the great chain” (probably the Bitter Root Range). Itis not 
the same, however, as the S. hudsonius var. @ of Richardson, as supposed 
by Bachman. This is the origin of the name réchardsoni, which appears to 
have no synonyms. 
Var. fremonti was first described by Audubon and Bachman, in 1853, 
from a specimen collected by Frémont in the vicinity of the South Pass. A 
second specimen, from Sawatch Pass, was described by Baird in 1857, at 
which time these two were the only specimens known. This form is also 
fortunately without synonyms. Gray, in 1867, regarded it asa variety of S. 
douglassi. 
Since 1857, when Professor Baird treated each of these forms as dis- 
tinct species, the material available for their study has vastly increased. The 
specimens of var. fremonti have increased from the two then known to 
upward of fifty. The five specimens of var. s?chardsoni have increased to 
upward of forty. Many additional examples of var. dowglassi have also come 
to hand, together with a large series from Northwestern Wyoming, collected 
under the auspices of the present Survey, illustrating the unquestionable 
intergradation of the Rocky Mountain forms with the eastern or hudsonius 
type. While this additional material places beyond reasonable doubt the 
complete intergradation of these diverse geographical forms, the exact 
boundaries of their respective habitats remain yet to be determined, as well 
