Three new shrews of the genus Cryptotis

Vol.

XXIV,

pp. 221-224. October 31, 1911

PROCEEDINGS

ofTin:

BIOLOGICAL SOCIETY OF WASHINGTON

uj

L

THREE NEW SHREWS OF THE GENUS CRYPTOTIS.

BY GERRIT

^S.

MILLER,

^Jr.

[By permissionof the Secretarj ^oitheSmithsonianInstitution.]

Among

^the

Mexican and

Central

American shrews

in the

United

States

National Museum

^arethree

specimens

of Cryptotis

which

^{differ so}

widely from members

of the described species that

each must

be

regarded

^as the representative^ofa

new form.

Cryptotis gracilis sp. nov.

Type.—

^{Adult (skin}

and

skull) No. Hfff> U. ^{S. National}

Museum.

Collected at head of Lari River, nearbase of Pico Blanco,Talamanca, Costa _Rica,by Win.

M.

Gabb. Altitudeabout6,000 ^feet.

Diagnosis.

—

Size

and

general appearance^{as in}the Cryptotis mexicana group (including the Costa RicanC. orophila)^{; skull}narrow and^elon- gated, ^this peculiarity

more

pronounced than ^{inthe small}G. tropicalis and C. soricina.

Color.

—

Entire animal a dark smoke-gray, ^the upperparts heavily washed with^blackishbrown, the general^effectdarker

and

less

plumbeous

than ina skinofC. orophilatakeninFebruary; under-colorslate-gray.

Skull.

— The

skullaboutequals that^of CryptotismexicanaorC.orophila in length, but the width throughout ^is noticeably less,this peculiarity equally appreciableⁱⁿ braincase,interorbital region,rostrum,

and

_palate.

Braincase nearlycircular inoutline

when

viewed fromabove, the ^lateral angles barely indicated; viewed from _behind,itisconspicuouslynarrower in proportion ^{to its} depth than ^{in C.} mexicana and C. orophila and appreciably

more

so than in C.soricina

and

C. tropicalis. While the braincase retains essentiallythe

same

_depth as in the other_{species of} similar size, therostrumislower, sothat the general outline of skull in lateralview is

more

strongly cuneate. Antorbital foramen smaller than inC. mexicanaor C. orophila, butin

same

_position,its posterior border over spacebetweenin¹

and m

^2. Mandibledecidedly

more

slenderthanin mexicana and orophila, but notpeculiarⁱⁿform.

Teeth.

— _Upper

incisors

and

unicuspids similar ⁱⁿ general^to those of 42—Peoc.Biol. Soc.Wash., Vol.XXIV,^1911. (221)

222

Miller

—

Three.

New

Shrewsof ^the

Genus

Cryptotis.

C. mexicana, the unicuspids showing

no

tendency toward ^{the con-} spicuously concave _posterior border characteristic of these teeth in C. orophila^; inner tubercleof unicuspids ^faintlydeveloped,

much

as in C. mexicana peregrina.

Upper

cheek-teeth sharing in the general reduc- tion of width characteristic of entire skull, this tendency especially noticeablein the largepremolar, theposteriorborderof which^isdecidedly shorterthanouter bonier, whileⁱⁿ C. mexicana and C.orophilathey^are about _equal; emargination of posterior borders slight, essentially as in mexicana

and

_orophila;hypocnes

somewhat

betterdeveloped than ^usual;

m

³ with well developed metacone and ^third commissure. Mandibular teeth less robustthanin C.mexicana

and

C. orophila but with no_special peculiarities ofform.

Measurements.

— _{Head and}

_{body,*70; tail,* 35;} hind _foot, 13.6(L2.4);

condylobasal length ^{of skull. 18.6 (} L9.4)t; lachrymalbreadth, 4.2 (5.0);

zygomatic breadth, ^5.2 (6.0); distance between zygomatic ^root

and

gnathion, 8.2 (8.2); breadth ofbraincase,9.0 (10.0); depth^ofbraincase, 5.4 (5.4); mandible,^10.4 (11.0); maxillarytoothrow (entire), 8.8 (9.0), mandibletoothrow(entire), 7.8 (8.2).

Remarks.

—

Three _very distinct species of Cryptotis are

now known

to occur in Costa Rica: the

medium

sized C. orophila on the Volcano of Irazu, C. gracilis ⁱⁿ Talamanca, and ^{the small C.} nigrescens ^at San.lose.

The

lastisfurther distinguished from thetwo othersby the reduced con- dition of the _posterior molar both above

and

below;

m

³ with mesostyle, metacone,

and

theircommissures_{very small} and_barelydifferentiated,

m

3

with posterior

V

reducedto a loop scarcely

more

than one-fourth as large asanterior V.

Cryptotis ^frontalis sp. nov.

Type—

^{Adultfemale(inalcohol) No. 123,429, U.S. National}

^Museum.

Collected near the City^ofTehauntepec, Mexico, by ^F. Sumichrast.

Diagnosis.

—

Size

and

_{general appearance} as in C. mexicana mexicana.

Skull with

more

robust rostrum

and

with braincase unusuallydeepened posteriorly,andrising anteriorly at a

much more

conspicuous angle^{(in this} respect noticeably surpassing ^C. nelsoni); teeth larger than in true mexicana butinner tuberclesof upper unicuspids ^less developed, though retainingdistinctly pigmented tips.

Measurements.

— Head and

_body,06; tail, 27; hind _foot, 12.2 (11.0).

Skull: condylobasal length, 19.0(18.6)1; zygomatic breadth, 6.2 (6.0);

lachrymalbreadth,5.0 (5.0); breadthofbraincase, 10.2 (10.0); depth^of braincase, 6.2 (5.6); mandible, ^10.(i (10.0); maxillary toothrow, ^8.6 (8.6); mandibulartoothrow,8.0 (8.0).

*Approximate^; fromskin.

tMeasurementsinparenthesis arethose ofanadultfemale topotype ^ofC.orophila (No.116,649)^.

tMeasurementsinparenthesis arethose ofan adult female topotypeofC.mexicana mexicana.

Millet

—

Three

New

Shrews _ofthe

Genus

_Cryptotis.

223

Cryptotis pergracilis

macer

eubsp. nov.

Type.

—

Adult female (in alcohol) No. _Iffff, near Guanajuato City, Mexico, by ^A. Duges.

Characters.

—

Similarto Cryptotis pergracilis pergracilis Elliot,butwith third upper unicuspid relatively larger, ^its area

when

viewed from the side distinctly

more

than half thatof firstunicuspid.

Measurements.

— _{Head and}

_{body, 50; tail, 17.4;} hind _foot, 10 (9.2).

Skull: condylobasallength,

—

_(16.0)*; from gnathionto posteriorborder of parietal ⁱⁿ

median

_line, 14.0 (13.8); zygomatic breadth, 5.0 (5.0);

lachrymal breadth,3.6 (3.6); mandible, 8.4 (8.4); maxillary toothrow, 7.2 (7.0); mandibular_toothrow,6.6 (6.4).

Remarks.

—

In three specimens^of Cryptotispergracilis pergracilisfrom Ocotlan,Jalisco,the typelocality,the thirdupperunicuspid^isuniformly

lessthanhalf as large as^first

when

viewedfromouterside.

*Adultfemale,Topotypeof pergracilis.