518 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
of the upper parts, and pure, being not mixed with any dusky, and the color 
extending to the roots of the hairs. The entire under parts, including the 
whole fore leg, the hind feet, and inner sice of hind leg, are snowy white, 
the hairs having no basal color. The tail is obscurely bicolor, white below, 
and not very sharply colored above to correspond with the areas of the body. 
Very young specimens, though nearly full grown and showing a sharp 
lateral streak, are more simply colored above than the adults, being grayish, 
with extremely faint buffy lining, instead of sharply blackish and buff. There 
is also observable, in the series before me, a tendency to exhibit two differ- 
ent tones of coloration. Those from dry regions east of the mountains are 
mixed grayish-brown and grayish-buff, with the lateral pale buff stripe not 
very conspicuous. In New Mexico, Southern Texas, and southward, the ani- 
mal frequently assumes a ruddier shade of the light color, mixed with much 
less blackish; in these, the lateral stripe is quite indistinct, because the upper 
parts in general are not very different. But the distinctions in these cases 
are not strong enough to require anything further than this notice of the fact. 
The following table of measurements will illustrate the size and shape 
of the species very fairly, and to some extent expose the range of variation :— 
TABLE IV.—Measurements of eighteen specimens of CRICRTODIPUS FLAVUS. 
| - a 
t & From tip of nose to— eee Length of— g 
: 3 ae 
} =) Locality. 6 = 4 3 
3 + ate eth eel olf ce Ps 
é a | ciel onl oe esol et en sean ee g 
é elel|a/é|élelale lal] ¢ 
ly26L5:| SMillciRiverMont-s > csce (-2-<aseeeces eoeeenioaee| wees 0.40 | 0.75 | 0.95 | 2.25 | 2.15 |...... 0.30 | 0.70 | Alcoholic 
11666 Montana Oeeer ase x Dry. 
| 4331 | Yellowstone 70 | ..-.do. 
| 3097 Black Hills b . i ----do, 
| 2614 | Ree Fork, ‘ Neb.” Alcoholic. 
1931 | Republican River, ‘‘ Neb.’’.......-....22.:--.--- |..< ---- do. 
Sade | MIAOU SM ON Kast e aelem mr eteiaie late wala alle eialee ee eee |e Dry. 
W340i) S527. GG) 5 Seca tao coast basscadceesacceens ! sos fe) Alcoholic. 
3050)|| 'Pole'\Creeke.. 2-02 santas tocenceaeceteeeisisa eens | ee Dry. 
4872) (Fort Uaramioi~s-sckeesssceseescea==aa eee are co} Alcoholic. 
342 Hort Dliss: NwMexe sc -.---sse beeper eee eee o == aos 
270. "Cimarron, N. Mex !.255- sccm: seeeen aoe se ceaeeeece ce Dry. 
seceee JAS TAO TE Sea apse Sea ob ereoeince sceeeccoeeassaces-)| © Alcoholic. 
es3ced|) gabene CR SSS Se ase eeemrse eee seaeeccorcpseecticel| ee ----do. 
1041 | El Paso, Tex ........ ad == eno: 
EAST SanvAntonio wlexrscuasan c= seo. ecee eee eee eon] 0.45 | 0575) | 10595) | (2520) 72°90) 2o=—. 0.30 | 0.60 | .-..do. 
Oe OUANA'. cnn w a akon cmiehee sca cadeecte ec se ates ----| 0.40 | 0.70 | 0.85 | 1.85 | 1.60 }.-.-.- 0.25 | 0.55 | .-..do. 
2013) | SVR CaM Oras} see - 5. svosat clas ceceases oes os coe ceee ---| 0.40 | 0.80 | 0.95 | 2.15 | 2.40 |...... 0. 35 | 0.65 | ...-do. 
Nghe Alveraper ens teks sa oe hos. So hate toll 0.42 | 0.74 | 0.90 | 2.07 | 2.06 |...-.. 0.30 | 0.63 
