Four new rodents from California

Vol. XXI, ^pp. 145-148 June 9,

1908

PROCEEDINGS

OFTHE

BIOLOGICAL SOCIETY OF WASHINGTON

FOUR NEW ^{RODENTS FROM} CALIFORNIA.

Among

the California

mammals _remaining undescribed

inthe collectionofthe Biological

Survey

^are

two Pocket Gophers from

the Sierrafoothills,

and two Meadow Mice —

one, a representative of the

mordax group, from

the

San Bernardino Mountains

in

Southern

California, the other, a

member

of the

subgenus

Chilotus,

from South Yolla

_Bully

Mountain, a high summit

of

the inner Coast Range ^west

^ofthe

Sacramento

Valley.

The new forms may ^{be known from}

the following descriptions:

Microtus mordax

bernardinus subsp. nov.

Type from

Dry

Lake, San Bernardino Mountains, ^{California (altitude} 9,000feet,atnorthbase San Gorgonio^Teak). No._150,632,U. S.National

Museum,

Biological SurveyCollection. cTad. CollectedAugust21, 1907,

by Vernon

^Bailey. Original No. ^s74'.».

Characters.

—

Similar externally ^to

M.

mordax.

Cranialcharacters.

—

_{Skull, contrasted with that ofmordax,}

_somewhat

heavier

and more

_{angular; zygomata}stronger

and more

spreading, nasals longer, broader_anteriorly; frontalanteriorly

more

elevated

and

_broader, with nasal

and

_{zygomatic processes} (especially the latter)

much more

strongly developed.

Measurements _{of typespecimen (in} flesh).

—

Total length, 180

mm.

; tail vertebra?,56; hind foot, 21.

x

Remarks.

— The

_BiologicalSurvey has specimens ^{of this}form collected

by

Frank StephensⁱⁿAugust, 1903, onthe ridge south ^ofBear

Lake

(alti- tude 7,800feet),

and

from the

same

locality collected

by Vernon

Baileyⁱⁿ August, 1907, in addition tothose from thetype locality atnorthbase of

San

_Gorgonio

Peak

(also

known

as

Gray

^{back). Ihaveseentwoadditional} specimens, ^collected

by

Joseph Grinnell, from South

Fork

Santa

Ana

Kiver.

Microtus

oregoni adocetus subsp. nov.

Type from SouthYolla BollyMountain, California. No. _137,995,U.S.

National

Museum,

BiologicalSurveyCollection, c?ad. CollectedJuly30, 1905,

by

^{A.S.Bunnell. OriginalNo. 135.}

21—Peoc.Biol. Soc. Wash., Vol. XXI,^{1908. (145)}

146 Merriam — _{Four New Rodents}

from

California.

Characters.

—

Size large fora Ghilotus; ears smallandnearly concealed inthe _fnr; colorofupperparts sepia or reddishsepia brown, very

much

paler than _oregoni; underparts ^dull buffy, the dark underfur showing through; ^tail

dark

brownish, palerbelow; ^feetwhitish.

Cranial characters.

—

Skull similar to that of oregoni hut _larger and heavier, with _{longer rostrum, larger} and less depressed nasals,

much

largeranterior_nares,

and

larger teeth.

Measurements.

— _Type

_specimen: Total length, 172; ^tail vertebrae, 4!);

hind_{foot, 21.} Cranial measurements: Basallength,24.5; basilarlength ofHensel,23.5; zygomaticbreadth,1(3; palatallength ⁽notchto incisors), 13.

Thomomys mewa

sp.

now*

Type from

Raymond, Madera

County, California. No. _133,183, U.S.

National

Museum,

BiologicalSurveyCollection, c? ad. Collected

June

28, 1904,

by

^{N. Hollister. (}JriginalNo. 908.

Characters.

— _Not

_closely related to

any known

_species. Size rather small; has

two marked and

_widely differentpelages;

summer

pelage ^red above

and

_{below, varying} from fulvous to almost ferruginous; winter pelage dusky

(much

darkerthan typical bottx), overlaid by^a light pep- pery

wash

ofrusset

brown

; underparts^inwinterdark plumbeousstrongly

washed

withbuffy ochraceous.

Cranial characters.

—

Skull peculiar; smaller than either bottseor

pa

^s-

calis

and

_{slightlylarger} than navus

—

_{from which}latter itdiffers insuch radicalcharacters asnottorequirecomparison {navus having^{the nasals} exceedingly small

and

_short,the

zygomata

widelyspreading posteriorly, theupper^incisors projecting strongly forward). Nasals rather longand straight-sided as inpascalis (notnarrowedposteriorly

and expanded

^ante-

riorly as in botUe);

zygomata

rather squarely spreading, with strongly

marked and

thickened anterior angle; ^bullae

and

premaxillse normal, ^as inbottse; temporalimpressions nearlyparallel

and

4-5

mm.

_apartinadult males; interparietalsuhquadrate,convexanteriorly.

The

_typespecimen

is in themolt

and

the

new

_{red pelage}which covers all but the

rump

^is

stillshort

and

_paler thanthefull

summer

_pelage.

Measurements.

—

Total length, 225; ^tailvertebrae, 60; hindfoot, 27.

Range.

— _{The Upper}

_Sonoran or Digger Pine ^belt along the west ^flank oftheSierrafrom northern

Tuolumne County

^southto

Kern

_Valley.

Thomomys

alpinus

awahneet

suhsp.

now

Type from Yosemite Valley, California. No. _133,076, U. S. National

Museum,

Biological SurveyCollection. 9 ad. Collected

June

14, L904,

by

^{N. Hollister. OriginalNo. 870.}

Characters.

—

_Sizerather small; similarⁱⁿgeneral toalpinus hut smaller, withdecidedly smaller^foreclaws

and

skull.

*Namedfromthe

Mewa

Indians,withinwhoseterritory thetype regionlies.

tNamedfromAhwahnee,the original IndiannameofYosemite Valley; usedalso forthebandorsubtribeinhabitingthe valley.

Merriam — _{Four New Rodents from}

California.

147

Color.

—

Muzzle

and

inner side of opening ^of cheek pouches usually dusky; winter pelage dusky, lightly

washed

withsepiabrown, sometimes

becoming

ochraceous on sides ofneck;

summer

pelage varying from^dull russet

brown

toalmostochraceous, brightest

on

sides ofneck

and

(lessso) on Hanks.

Cranialcharacters.

—

_{Skullresembling}thatofalpinus but

much

smaller;

nasals small

and

narrow anteriorly, with sides nearlyparallel; interpar- ietal broader than long; zygomata not broadly spreading, broadest pos- teriorly; bullaesmall

and

smoothly rounded,lacking the antero-external prominence^ofalpinus; occiput bulging.

Measurements.

— _Type

specimen, 9 ^{ad.: Totallength,104; tailvertebrae,} 54; hind_foot, 28.

An

adultmale from_type locality: Total length, 194;

tail vertebrae, 09; hind foot, 27.