109 
Skull Measurements. Type (female) : condylo-basal length, 19; zygo- 
matic breadth, 12-5; mastoidal breadth, 12; interorbital breadth, 4-7; 
incisors to postpalatal notch, 10-5; foramen magnum to postpalatal 
notch, 9-0; fronto-palatal depth at middle of molar series, 8-0, Allotype 
(male): condylo-basal length, 18; zygomatic breadth, 11-5; mastoidal 
breadth, 12; interorbital breadth, 4-8; incisors to postpalatal notch, 9-2; 
foramen magnum to postpalatal notch, 8-8; fronto-palatal depth at middle 
of molar series, 7-5. 
Comparisons. Z. p. kootenayensis is readily differentiated from 
Z. p. princeps of the Rocky Mountains region by its paler, dusty colour. 
Compared with a large series of Z. p, oregonus (including topotypes), 
kootenayensis is noticeably duller and paler in colour, both in average 
appearance and in nearly all individual specimens. The oregonus specimens 
superficially look more like specimens from western Alberta (Waterton 
Lakes, Banff, and Jasper parks). Topotypical specimens of oregonus have 
head and mid-dorsal area more finely flecked with the yellowish colour of 
the sides. Z. p. kootenayensis also averages larger and more greyish than 
the three subspecies recently described by Dr. E. Raymond Hall 1 , Z. p. 
cinereus (Utah), and Z. p. curtatus and Z. p. palatinus (Nevada). Twenty- 
five specimens from Oregon (including two topotypes), and twenty-four 
specimens from Idaho, in collections of United States Biological Survey, 
referred to oregonus, were examined and compared with our specimens of 
kootenayensis , in 1931. The cranial characters of Z. p. oregonus as given 
in Preble’s monograph 2 are as follows: 
“Compared with Z. princeps from Colorado, the skull of the present form differs as 
follows: brain case more rounded, especially shorter and more rounded behind; zygomata 
shorter; incisive foramina larger and very much broader behind; audita! bullae smaller." 
The only one of the above characters that seemed to hold good in a 
considerable number of specimens (Preble had only nine specimens — eight 
from Oregon, and one from Nevada, when he described the subspecies 
oregonus ) was that the incisive foramina were larger throughout in oregonus 
and very much broader posteriorly. The incisive foramina in kooten- 
ayensis are much narrower throughout and not greatly broadened in most 
specimens, although kootenayensis shows some signs of intergradation with 
princeps and oregonus in this as well as in some other characters. No 
particular difference could be detected in roundness of brain case poster- 
iorly, but Kootenay specimens have skulls noticably narrower both in 
brain case and breadth of zygomatic arches. No specimens were taken 
from Osoyoos Lake country in southern Okanagan valley, possibly because 
the local conditions were too dry, but a series from Oroville, Okanagan 
county, Washington, are apparently referable to kootenayensis. A single 
female specimen was taken on Meadow creek, near Yahk, East Kootenay 
district, a few miles north of the Montana-Idaho-British Columbia corner, 
September 1, 1929, which is distinctly referable to kootenayensis , but a 
series of ten specimens taken in May, 1930, near Newgate, at edge of 
Tobacco Plains, on east side of Purcell range, are plainly referable to 
Z. p. princeps. 
iCritical comments on mammals from Utah, with descriptions of new forms from Utah, Nevada, and Wash- 
ington; Univ. California Publ. in Zoology, vol. 37, No. 1, pp. 1-13 (April, 1931). 
Revision of the Jumping Mice of the Genus Zapus; North American Fauna, No. 15, p. 24 (Washington, D.C., 
1899). 
51326 — 8$ 
