MURIDZ—ARVICOLINA]—ARVICOLA RIPARIUS. 173 
TaBLe XLIV.—Measwrements of thirty-nine dry specimens of the rivarius type from various localilics in the 
United States west of the Mississippi—Continueds 
g 3 
B ; |3 3] 5 
= Date. Locality Collected by— = a 5 a Remarks. 
od | May 28, 1858 | Fort Bridger, Utah...... GC: Drexler... ---- 4.75 | 2.10 | 0.78 
9 | June 9, 1858 SOOr eae ce coe se 3.75 | 1.00 | 0.70 
o | June 4, 13858 Bl eect eas petein deel Neceratala 0.79 | 
-cSopdese. a5 KE. -Palmer.-.-.-2=.|)d. 90), -.-20)/0. 74 
OO) ea. cwatee ee «Tl Pears 0. 62 
Js Meiner: <2. --- 4.50 | 1.30 | 0.79 | Dark-colored. | 
do:-gs2-<5-50 5 5.00 | 1.50 | 0.77 |....do. 
do 4.75 | 1.35 | 0.85 -.do, 
( saasaaenaeane 4.25 | 1.95 | 0.78 |....do. 
5560 (UY) pak aooseccbecss se PaeGO apsosce sess |} eh ee ety OMe aa oiler, 
-| Fort Tejon, Cal ..-...-.. J. Xantus.........] 4.00 | 1.65 | 0.90 
-| Upper Pit River, Cal....} J.S. Newberry.-..| 4.50 | 1.50 | 0.73 | Type of “longirostris”’. 
-| Lost River, Cal .......-.. seen) ackeoceseasas 4.50 | 1.55 | 0.81 | Labeled “ montanus”’. 
Petaluma, Cal .---...-.. I. Samuels...-----| ..... 1,60 | 0.80 | Labeled ‘ montanus ?". 
Monterey, Cal ...-...--. A.S§. Taylor. .-.-- 4.33 | 1.80 | 0.83 | Labeled * edaz?’’. 
San Diego, Cal.......-- J.F.Hammond ..} 3.40 | 1.40 | 0.80 | Labeled ‘‘edax"’. 
sO wae Sos eaxsocs 4.40 | 1.85 | 0.88 | Labeled “ edaz ?”. 
J. LeConte 2.2.22! 4.00 | 1.55 | 0.90 | Type of “edax”. [“edax”’. 
=e5a6 do ...............-.| U.S. Ex. Exp ... | 3.80 | 1.45 | 0.83 | Labeled ‘‘ californicus”’; like 
ean do}. -....-.-=....-..] -..00 ..-.......---| 4.00 | 1.75 | 0.80 | Type of “californicus”’. 
Puget Sound..-......-.. eadowee-se see: 3.50 | 1.87 | 0.87 | Type of * occidentalis”. 
EXON BEB peS=me oh sono reps cree asoos3 4.18 | 1.53 | 0.79 
As will be seen, this series embraces the type-specimens of all the 
nominal species we are to discuss except “montana”, and of this there is 
a typical example. The series was made up without the slightest reference 
to any desired or expected result, and simply includes, in fact, ad/ the dry speci- 
mens that have come under our observation. The seven specimens marked 
“young” are not grown enough to furnish available measurements; and as 
they would vitiate the result if included, they are omitted in computing the 
average. 
It is hardly necessary to more than allude to the average of this series 
as"compared with the eastern ones. The total length falls between that of 
the Philadelphia and the Illinois series, and is 0.15 below the general average. 
The length of tail is within a just appreciable fraction of the grand eastern 
average, taking place between that of the general series and the Illinois 
series. The average proportion of body and tail is (4.18 : 1.53) as 1.00 to 
0.34, precisely as in the Philadelphia and Massachusetts series. The average 
foot is precisely as in the Illinois series, and within 0.01 of the grand eastern 
average; only two feet touch 0.90, and none (of the adults) fall below 0.70. 
