_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 | ---------------+-----------+---------+----------+---------+----------- No. specimens | 11 | 7 | 18 | 20 | 10 | | | | | Total length | 180.5 | 176.7 | 179.1 | 186.2 | 196.0 | 170-199 | 166-188 | ..... | 170-210 | ..... | | | | | Tail-vertebrae | 85.5 | 85.0 | 85.3 | 94.5 | 100.0 | 72-101 | 75-93 | ..... | 83-104 | ..... | | | | | Hind foot | 23.1 | 23.6 | 23.3 | 23.8 | 21.0 | 22-24 | 22-25 | ..... | 22-25 | ..... | | | | | Ear from notch | 18.2 | 19.1 | 18.5 | 18.4 | ..... | 17-19 | 18-21 | ..... | 14-21 | ..... | | | | | Greatest length| 27.9 | 28.3 | 28.1 | 27.8 | ..... of skull | 26.8-29.0 |27.9-28.9| ..... |26.6-29.1| ..... | | | | | Length of | 10.4 | 10.2 | 10.3 | 9.9 | ..... nasals | 9.9-10.8 | 9.5-10.7| ..... | 9.1-10.4| ..... | | | | | Zygomatic | 14.3 | 13.5 | 13.9 | 13.8 | ..... breadth | 13.9-15.0 |13.0-13.9| ..... |13.3-14.4| ..... ---------------+-----------+---------+----------+---------+-----------