64 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY—GENERAL REPORT. 
" S. argentatus. 
S. aquaticus. 
foil- 
958. 
\W- 
Length, of skull.-------_--------_ 
1. 54 
1. 40 
1.30 
Greatest width_ 
.80 
.75 
.70 
.67 
Least interorhital space_ 
.33 
.32 
.30 
.31 
Wicfth of nose--- 
. 20 
. 20 
. 15 
. 16 
Length of palate_- — 
.72 
. 69 
. 67 
.60 
Width outside the molars_ 
.45 
.42 
.38 
.39 
** From St. Louis. 
Measurements. 
Current 
number. 
Locality. 
Nose to— 
Tail to end of— 
Length of— 
Breadth of 
palm. 
Nature of spe¬ 
cimen. 
Occip 
Root of 
tail. 
' Verteb. 
Hairs. 
Hand. 
Foot. 
1922 
West of Fort Riley _ _ 
1. 75 
6. 25 
1. 00 
1.12 
. 78 
From alcohol 
2236 
Alton, Ill... 
1.80 
.88 
. 85 
. 94 
Specimen _ _ _ 
2196 
St. Louis, Mo_ 
1. 90 
4. 98 
1.12 
. 90 
_ _--do_ 
2197 
1. 93 
5.15 
1.15 
. 80 
_do-------- 
2199 
1. 80 
4. 67 
.71 
_do__ 
2200 
_do_ 
1. 74 
5. 10 
. 70 
_do. - - - - 
2176 
Fort Smith, Ark_ 
1. 73 
4. 74 
. 70 
__do__ 
2186 
Prairie Mer Rouge, La_ 
1. 82 
4. 63 
. 82 
_do_- 
2214 
Columbus, Ohio.. 
1.89 
4. 38 
1.12 
1. 29 
.90 
.85 
.83 
-do. 
This species was first described from a specimen collected in Michigan by Dr. Geo. Leib. It 
is essentially a prairie species, where it replaces the S. aquaticus of the east. Its extreme range 
to the west has not yet been ascertained. 
List of specimens. 
Catalogue 
number. 
Corresponding 
No. of skull. 
No. of 
specim’s. 
Locality. 
Whence obtained. 
Nature of specimen. 
773-5 
Tremont, Ill__ 
W. J. Shaw. 
Dry skin 
1029 
2016 
Alton. Ill. 
R Kennicott___ 
Alcohol 
? 2214 
Columbus, Ohio_... 
L. Lesquereaux_ 
14 
St. Louis, Mo_ 
Dr. Engelmann_ 
Dry and in alcohol- 
13 
Prairie Mer Rouge, La_ 
J. Fairie_ 
Alcohol 
2176 
Fort Smith, Ark_ 
Lieut. Whipple_ 
do _ . 
1760 
Mouth cf Big Sioux, Nebraska.. 
Lieut. G. K. Warren and 
Skin . 
Dr. F. V. Hayden. 
1922 
20 miles west of Fort Riley, Kan. 
Lieut. F. T. Bryan and 
Alcohol _ __ _ 
W. S. Wood. 
