Proceedings of the Biological Society of Washington

VOL. _XIII, PP. 75-78 SEPTEMBER 28, 1899

PROCEEDINGS

OFTHE

BIOLOGICAL SOCIETY OF WASHINGTON

NEW TREEFROG FROM THE DISTRICT OF COLUMBIA*

BY GERRIT

S.

MILLER,

^Jit.

In June,

1893,

Mr. W.

P.

Hay ^added

^to

^{the known fauna}

^of

the

District of

Columbia

f a treefrog

which he found

in

consid

erable

numbers

in

a marsh

at

Mount Vernon,

Virginia.

He _pre

sented eighteen specimens

^of

the animal,

identified as

Hyla

^cinerea

(Daudin) (=H.

^'carolinensis^J_), to

the United

States

National Museum. Two

_yearslater

Mr. Hay

^collected

specimens

^{at Little}

Hunting

Creek,

Va. Four

of these are

now

in

the National Mu

seum. This

_frog

was

first

brought

^to

my

notice early in

June,

1898,

when,

ⁱⁿ

company ^{with Mr.}

^A.

H. Howell,

^I

heard

itsnotes, strikingly ^different

from

those of

the other batrachians

of

the

region,^at

Four Mile Run, ^Va. A week

later

seven were _captured here by ^{Mr. Howell} and Mr.

E. A. Preble.

Since then we have

taken, in

the marshes

at

Four Mile Run and _Dyke, a

_locality

between Alexandria and Mount _Vernon,

_Virginia,

about

_thirty individuals,

some

of

which

I

have had

in captivity ^for

over a

year.

Comparison

^ofthese

^with

living

examples

^of

Hyla

^cinerea

from Bay

^St.Louis,Miss.,

shows

that

the northern and southern forms

are readily distinguishable

from each other by

^characters

of

both form and

color.

Most conspicuous among

^{these is}

^the normal absence

in

the northern animal

of

the

_stripes

on

sides

*Published

by

permission^ofthe Secretary of thoSmithsonianInstitu tion.

t

The

^'faunaof theDistrictof

Columbia

^' isgenerallyunderstoodtoin clude that of the regionwithin aradius oftwenty^milesfromthe Capitol.

19-Bior,Soc.WASH.,^VOL.XIII,1899 (75)

7<>

Miller A Neiv

_Trccfrog

from

^tlic District of

Columbia.

and

_legs so

conspicuous

ⁱⁿ

Hyla

^{cmerea. It}

may

^therefore

^be

called:

Hyla

^evittatasp. nov.

Type^adulttf (in alcohol)No._26,291,UnitedStatesNational

Museum,

collected at

Four

Mile

Run,

Alexandria County,Virginia,July 15, 1898,

by

^{Gerrit8. Miller, Jr.,}

and Edward

A. Preble.

Zonal_position. This _frog is probably ^{confined to the}

Upper

^Austral zone.

Geographicdistribution.

While

the animal is at present

known

from the marshesof the

Potomac

River near

Washington

only,^{it isto}be looked fornearthe coastfrom

Chesapeake Bay

^to

Long

^IslandSound.

Generalcharacters. Like

Hyla

^cinerea(Daudin) but withbroader,deeper muzzle

and

normallyunstriped

body and

legs.

Color. Entire dorsal surface varying from olivaceous

brown

_through deep myrtle-green^topaleyellowish grass-green^; ventral surface white, irregularly tinged with yellow, especially

on

chin

and

_throat; colors of back

and

belly fading rather abruptly^into each other

on

lower _{part of} sides; skin of

under

surface oflimbs unpigmented,transparent^; legs

and

jawsslightlypaler

on

sides than above_; eye verybright

and

iridescent, the _pupil black, the iris golden greenish yellow, thickly dotted with black; back with a few _usuallyless thanhalf a

dozen

inconspicuous, minute, yellowish ^dots.

Measurements.

Type:* head and

body, 48;

hind

_{leg, 69; femur, 20;}

tibia, 21; tarsus, 11; hind_foot, 17; humerus,⁸; forearm, 8; front^foot, 10; greatest width of head, 14; eye ^to nostril, 3.5; distance

between

nostrils,^3.5.

An

adult

$

^{from the type locality:}

^{head and}

^{body, 50;}

hind_leg,70; femur,²¹; tibia, 21; tarsus, 11 ; hind _foot, 17_; humerus, ⁸;

forearm, 8; front_{foot, 10;} greatest widthofhead, 14; eye^to nostril, 4;

distance

between

nostrils, ^3.

Remarks. Hyla ^{evittata is at}once distinguishable from H. cinerea, its

only near ally,

by

the absence of the _stripes

on

sides

and

_legs,socon spicuous in the ^latter.

Except

^for the differences in the shape^ofthe head,the

two

animals _{agree perfectly} in form

and

dimensions.

Hyla

evittata, however, probablyaveragesslightlylargerthanH.c-nerea.

The

peculiarities intheformofthe

head

are

more

readily seenthandescribed.

Tn

Hyla

^evittatathe outline ofthe muzzle

when viewed

fromaboveisdis tinctly

more

_bluntly

rounded

thanin H._cinerea,

and

asaresult the nos

trilsarewider_apart

and

lessdistant bothfrom _eyes

and

_tip ofmuzzle.

Viewed

from the _side,the depth from ^{nostril to}

mouth

is perceptibly greater in H. evittatathan inH. cinerea.

The

granulation of the skinof belly

and

hind_legsisidentical inthe

two

animals. These comparisons

are entirelybased

on

living individuals.

*An

adult_tfH. cmerea

from Bay

^St.Louis,Miss.,measures:

head and

body, 48; hind_leg, 68; femur, 20; tibia, 21; tarsus, 11; hind foot. 15;

humerus, 9; forearm, 9; front_foot, 10; greatestwidth of head, 13; eye to nostril, 4; distance

between

nostrils, 2.5.

A New

_Treefrog

_from

the Disfn'ri of

Columbia. 77

Color variation inHyla ^{criilala is}verygreat,

and

as inothertreefrogs chieflydependent onthe character of tliesurfaceon whichtheanimalis resting.

When

_searchingforfood

among

^{the leaves}

^and

^stemsof pickerel

weed and

_pond-lilies,

Hyla

^{evittataassumes a}yellowish grass-greentint, closelyharmonizing with the color of the_plants. Incaptivity the color isusually darker

and

duller, this tendency culminating ^{in rich}myrtle- green

and

darkolivaceous

brown

inindividuals thathaverestedon

brown

barkorhave remained long hidden^{in a}dark corner.

The

colorduring hibernationunder

moss and

sodis

much

_palerthanthat

assumed by

^the

same

individuals

when

hiding ^{in similar} places during ^the

summer.

However

_{great thechanges}in color

may

be, at

no

timeistheredeveloped

any

^{traceofstripes. If rudiments}of these are present they^arealways

visible. Similarlyⁱⁿ

Hyla

cinerea,

which

_undergoes

an

_{exactlyparallel}

series of color changes, the stripes are never affected in distinctness, though they^are

most

conspicuous

when

the general color oftheanimal offersthe greatest^contrast.

The

_stripesofHyla^cinereavaryin living in dividualsfrom_silverywhitetometallicreddish _gold.

The body

stripes arealmost_invariablybordered

by

^{anarrowblackline.}

When

theanimal

isinrepose the

body

stripesareabout1.5

mm.

inwidth,but

when

it isut tering^itsnotethe

body becomes

greatlyswollen

and

the_stripes broaden to three times their

normal

_width,

and

atthe

same

time

assume

their brightest ^colors.

The

leg stripes arenarrower

and

lesssharply^defined thanthe

body

stripes,

and

theirdark margins^{arelessconstantin}devel

opment.

As

totheconstancy^{of thecolor}differences

between

the

two

forms: I

have handled about

two

dozen _living

and

_freshly killed specimens of Hi/laevittata,

and

have probablyseen nearly as

many ^more

^atadistance

ofonly^afewfeet.

Among

^{these one}

^had

^a faintly developedstripe at the angle of the jaw.

Of

the twenty-two ^alcoholic specimens^collected

by

^Mr.

Hay ^and now

in the National

Museum,

eight

have

tracesofthe

body

stripe, which, however,ⁱⁿ noinstance is margined with black, or assharply^{definedas in those}southern specimens ⁱⁿ whichthe_stripeis

shortened

and

narrowed.

Of

_{sixty-onespecimens}ofHyla^cinerea(seven receivedalivefrom H. H.

&

C.8.Brimley,*^{the others}preserved^{in alco} hol in the U. S.National

Museum

_f) there ^is considerable variation in the leg stripes, but with only ^t\vo exceptions the

body

stripe, though varying ⁱⁿ length

and

_breadth, is conspicuously developed, ^{definite in} outline,

and

_usually margined with ^black. In the

two abnormal

indi viduals (onefrom

Bay

^St.Louis,Miss.,theotherfrom

New

Orleans,La.) the _legstripes are absent,

and

the

body

stripesreduced to

mere

traces near the angle of the jaw.

When

forwarding the unstriped specimen fromMississippi, theMessrs. Brimley wrote ^{that it}

was

the only one^of the kind observed

among

^the large

number

that

have

passed through

*

Taken

at

Bay

^St. Louis, Miss.

t

From

the following^localities: Texas,

New

Braunfels; Louisiana,

New

^r

Orleans; Florida, Clear Water, Georgiana, Indian _River,

Lemon

_City,

Marco

Island, Pensacola; NorthCarolina, Beaufort.

78 Miller

.1 AV/r 7m;/ro//

from

^{tlt< Dixlr'n-t <>j (}

theirhands. Such individualsas these are readily distinguishablefrom the_faintlystripedspecimens^of Hyla^ccittala

by

^{theform of themuzzle.}

Habit*.

Very

^littleis

known

aboutthe habits of_Hi/laedttala. In

June and

_Julytheanimalsaretobe found inthe rank vegetation of the^tide marshes.

Here

they remain quiet during the day, butas evening ap proachesthey

become

active

and

_noisy. Their foodat this timeconsists chieflyofa small beetle that is found

on

the leaves of the pond-lilies.

The

noteislikethat ofHylapickeruigii inform, butin quality^{it is}

com

paratively harsh

and

_reedy, with a suggestion of distant Guinea-fowl chatter,

and

_{scarcely a}traceof the peculiar freshnessso characteristicof thesong^ofthe smaller_species.

The

songperiod continuesthrough

June and

_July. Laterinthe season the_frogsleavethelow

marsh

vegetation.

As

_theyare then _perfectlysilentthey^{are difficult}to find, though ^occa sionallyone

may

^{be seen in a}

^bush

^{or small tree, but never far from}

water.