176 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
TaBLE XLV.—Measurements of thtrteen alcoholic specimens of A. RIPARIUS from the United States west of the 
- Mississippi. 
Noreitons Tail to end | 
of— 
g Locality. Collector. “hs =; # z 3 Remarks. | 
2 a : z = 
g é Pa 3 t= = iS 2 = fo 
td i) o ° s ov CI S = 2 
A i) i) i} a > os] & iss) a 
7611 Fort Bridger, Utah* | C. Drexler .----- 0.48 | 0.98 | 1.18 | 4.50 | 1.20 | 1.30 | 0.38 | 0.70 | 0.50 
10042) 
to r Bede ae aseeteeoac Sadi Oaner Ronse Ihoodoe| [pscetel|aen ssl bessoa)|sSscos|asesel] Gap cellissossall) eSe% 
10067 J 
T7737 Ace ) Be Sy ieee OnE eee 
10068 |.--. 1.45 | 0.33 | 0.72 | 0.42 
10069 |.--.. 1.45 | 0.40 | 0.82 | 0.45 
10070 aes sce 1,90 | 0.38 | 0.77 | 0.55 
10071 SSO naeasseneneatod 4.00 | 2.00 | 2.15 | 0.40 | 0.80 | 0.52 
10072 | Carson Valley-..----- Pee Oe ee cece rene | Seba) opel | Sei ee=e5)| Seses|| Soe5-|se-css ase. 
7738 ~+| Yort Kearney. .-.---- Perils =aasoetcce 0.52} 1.00 | 1.25 | 4.75 | 1.80 ]...... 0.40 | 0.80 | 0.52 
1925 | Medicine Bow Creek) W.S. Wood..--. 0.40 | 0.80 | 1.10 | 3.20 | 1.19 |...... 0.57 | 0.70 42 
1269} | Klamath Lake.----- De SONG W DENI es | mea eae oat] Peete Peat! heel eee So pisces Sees Young. 
1270%4| Upper Des! Chutes 34h ee 100 ac terete am a | lente | eet | era | | eerie ene ee | 22.00: 
4835 | Upper Platte River | C. Drexler -..-... 0.50 | 1.00 | 1.25 | 4.00 | 1.85 | 2.00 | 0.40 | 0.80 | 0.55 
757L | Black Hills, Dak...) F. V. Hayden ...} 0.45 | 0.92 | 1.15 | 4.00 | 1.30 | 1.50 | 0.38 | 0.80 | 0.45 
10073 | Kort\Shaw, Mont ...| R.B. Hitz. .-----] <2. -2|) -.-- | coo} oe SUM bi bill! Sees 0. 76 me 
7624 Kort'Crogks Cal: >-<:| id; Wellner asso.) eae eo | etal erin! |e cere! esters | eer re et ee Young. 
7739 Fort Tejon, Cal.....| J. Xantus.....-. 0.55 0.57 
2526 | San Diego, Cal ..... | J.F. Hammond | 0.52 0.55 
9893 | Monterey, Cal ....-. Dr: 'Canlfield’=s || ccee| estan a weose | seme eee eee | eee cll homeo mean Young. 
ORIG adv a se be eet pee en ein Steal eared) petenecl| mad Deer eater cell See ee rere Rees Esso. 
10074 | | 
to =200\=,.coset eocans 8 waGO). ese sn eweell pear el lyseses| iscees | taem==|soeeee eee Asoq| Neeses| | eecre poeetiths 
10081 J 
* Drexler's numerous Fort Bridger specimens we haye not thought necessary to measure in detail, as they differ but 
little, and are precisely like the dry ones already presented. McCarthy's, from the same locality, show a good deal of difference 
in length and stoutness of tail. It will be observed that these specimens, which we cannot distinguish even asa local strain, 
from ordinary riparius, were collected in company with a lot of A. austerus var. decurtatus, which seems common in that 
locality, and is distinguishable at a glance. Even the collectors appear to have separated the two species, to judgo from tho 
labels. 
+ By some misprint in Baird’s work, Nos. 1269, 1270 are given as mounted, whereas they now lie before us in alcohol. 
Having exhausted our data of size and external shape, we will next inter- 
rogate an extensive series of skulls of eastern and western Arvicolas of the 
riparius section, to see if there be any cranial characters upon which more 
than a single species may be predicable. 
