he captive mice were studied. Data from
live-trapping and from snap-trapping are combined and provide some
knowledge of size and fluctuation of populations in the species.

Examination of the accumulated specimens and the captive mice reveals
the occurrence in southern Kansas of an unnamed subspecies, which may be
named and described as follows:

#Peromyscus boylii cansensis# new subspecies

_Type._--Male, adult, skin and skull; No. 81830, K. U.; from 4
mi. E Sedan, Chautauqua County, Kansas; obtained on December
30, 1959, by C. A. Long, original No. 456.

_Range._--Known from 3 mi. W Cedar Vale, _in_ Cowley County,
Kansas, and from the type locality.

_Diagnosis._--Size medium (see Table 1 beyond); underparts
white; upper parts Ochraceous-Tawny laterally, becoming
intermixed with black and approaching Mummy Brown dorsally
(capitalized color terms after Ridgway, 1912); eye
nonprotuberant; tail short but well-haired distally and
usually less than half total length; nasals long; cranium
large.

_Comparisons._--From _P. b. attwateri_, the subspecies geographically
nearest _cansensis_, the latter can be easily distinguished by the less
protuberant eyes and relatively shorter tail (91 per cent of length of
head and body; in topotypes of _P. b. attwateri_ from Kerr County,
Texas, 104 per cent; in specimens of _P. b. attwateri_ from Cherokee
County, Kansas, 103 per cent). _P. b. cansensis_ is darker than _P. b.
attwateri_ and darker than _P. b. rowleyi_, the palest subspecies of
brush mouse, which occurs to the westward. The skull and nasals (see
Table 1) in adults of _P. b. attwateri_ from Cherokee County average
shorter than in _cansensis_.

_Specimens examined._--Total, 26. _Cowley Co._: 3 mi. W Cedar
Vale, 16. _Chautauqua Co._: type locality, 10.

TABLE 1. AVERAGE AND EXTREME MEASUREMENTS OF SPECIMENS OF P. B.
CANSENSIS, OF P. B. ATTWATERI FROM CHEROKEE COUNTY, KANSAS, AND OF
TOPOTYPES OF P. B. ATTWATERI LISTED BY OSGOOD, 1909.

======================================================================
| _P. b. cansensis_ | _P. b. attwateri_
+-----------+---------+----------+---------+-----------
|Three miles| Type | Both |Two miles| Type
| west of |locality |localities|south of |locality[A]
|Cedar Vale | | | Galena |
-------