GONIOMYIA, 181 strongly converging towards the anterior branch of the fourth

vein ; discalcull clo8ed ⁱⁿ the majority of the specimens.

Common,

in

summer; Washington,

D. C.;

Trenton

Falls,N".

Y

,

etc.

Among

fifteen specimens

which

I

had

before

me, when

I first describedthis species, only one

had

the discal cell open.

2.

G. cogiiatella

0.S.

%

^{and 9-}

—

Sulphureo-flava, fusco variegata, aiitennis basi aurantiacis, inmaredense pubescentibus,verticillisbrevi- bus; pedlbus unicoloribus; cellula discoidali aperta.

Sulphur yellow, variegated with brown; antennje orange yellow at the basis,densely pubescentandwithshortverticilsinthemale; feetuni- colorous; discalcellopen. Long. corp. 0.2

—

^0.25.

Syn. Gonomyiacorjnatella0. Sacken,Proc. Ac.Nat. So. Phil.1859.p 230.

Very

like the preceding,but easily distinguished

by

the follow- ing characters:

The

antennae of the

male

are covered

on

every joint with a short,

dense

pubescence,which, being interrupted at the articulations,

makes

the antennae

appear

moniliform; the balteres (b«th

stem and knob)

are infuscated; the pleursE are yellow, with a

brown

stripe; thefeet are uniformly pale tawny, onlythe tipsof the tarsi darker; the discalcellis

open

(at least inthe

normal

specimens); the innerangle ofthe

marginal

cell is

more

acute, the prajfurca

running

obliquely from the first longi- tudinalvein; the anterior

branch

of the second longitudinal vein is

more

oblique,

and

therefore

somewhat

longer; the distance

between

the tips of both branches of this vein is

about

twice the length of thedistance

between

the tip of the anteriorbranch-and that of the first longitudinal vein; the third vein is straight, although, inits

whole

course,

somewhat

converging

towards

the anterior branch of the fourth ; the second

submarginal

cell is

somewhat

longerthanthefirstposterior.

The

forceps of the

male

(Tab.

lY,

fig. 18)has a

somewhat

differentstructure

from

thatof G. sidphurella.

Hah. Washington,

D. C. I

had

seven specimens. ,

3.

G. SUl)cilierea

0. S.

%

^and 9.

—

Sulphureo-flava; mesonoto cinereo-fusco; antennisnigris; pedibusunicoloribus; celluli discoidali

(inspeciminibustypicis) clausa.

Sulphur yellow; mesonotum grayish-brown; antennre black^;*feet uni- colorous; discalcell (inthenormal specimen) ^closed.

Syit. Gonomyiasubcinerea 0.Sacken,Proc. Ac. Nat. Sc. Phil. 1859,p.231.

182

DirTERA

OF

NORTH AMERICA. [PART

IV.

Rostrum

^{jellow, palpi}

^brown;

^{antennce black; those of the}

male have

moderately long verticils ; thorax sulphur yellow

;

mesonotum

grayish-brown; pleurse without

any brown

stripes, uniformly yellow^; halteres very slightly infuscated: leet pale

tawny Wings

(Tab. II, fig. 4) comparatively longer than in the preceding species; the discal cell is closed in

normal

speci-

mens

; the tip of the auxiliary vein is a little posterior to the origin of the prsefurca; the interval

between

the tip of the first

longitudinal vein

and

the anterior

branch

ofthe secondvein is fiveor six times shorterthan the interval

between

thetips ofthe

two

branchesof the second vein; the inner endofthe secondsub- marginal ^{cell is} pointed, verylittle anterior to the inner

end

of the first posterior cell; the third vein is straight

and

verylittle

convergent with the anteriorbranch of the fourth; theinner

end

of the marginal cell (angle of the prajfurca)

almost

acute; the innerends of the first

and

fourth posterior,

and

ofthe discal cell, nearly in one line.

Abdomen brown

above;

margins

ofthe seg-

ments

yellow; venter

and

forceps of the

male

yellow; the latter withlinear, hairy, slightly

dusky

appendages.

Hah. Trenton

Falls,

N.

Y.;

Washington,

D.C.

Among

twelve specimens, the discal cell is

open

in one only.

4.

G.

blaiida. 0.S. % and 9^•

—

^{Al?estigmateetmargiuisanterioris}

parte apieaiifiiscis; venulis transversis iiifuscatis; vense longitudinalis secund;e rami auterioris apex

cum

apice vense longitudinahs primse coincidens.

Wings

withthe stigma and the apical portionof the anteriormarginin- fuscated; cross-veins clouded; the tip of the anterior branch of the second vein is coincident with the tip of the first longitudinal vein.

Long. Corp. 0.25—0.28.

Syn. Gonomyiablanda 0. Sacken, Proc.

Ac

Nat.Sc.Phil. 1859,p.231.

Rostrum

gray,

margined

with yellow above; front

and

vertex gray,

margined

with yellow alongthe eyes; antennje

brown

;

two

basal joints yellow.

Thorax gray

above, with

two approximated brownish

stripesinthemiddle;

two

hardlydistinct lateral stripes;

scutellum brownish,

gray

in the

middle

;

metathorax

brownish ;

pleurjB pale yellow, slightly hoary; halteres duskj^ with

dark knobs

; feet pale yellow, pubescent; tips of the femora, of the tibiae,

and

the

whole

of the tarsi

dark brown

;

abdomen

grayish-

brown

_; lateral

and

posterior margins of the

segments

yellow

;

EMPEDA. 183

venter yellow;

male

forceps yellow,with black

horny appendages

(Tab.

IV,

fig. 17).

Wings with

the cross-veins

and

the inner

ends

ofthe basal cells,

and

ofthe second submarginal

and

second posteriorcellsclouded; the stigma

and

the portionof the anterior

margin between

^it

and

thetipareblackish; the pra^furca,strongly arcuatedat thebasis,isparallel,duringtheremainderofitscourse, to the first longitudinal vein ; thetipof the anterior branchofthe second longitudinal vein is coincident with the tip of the first longitudinalvein; the origin of the praefurca is alittle anterior to the tip of the auxiliary vein; the second submarginal cell is iongei* than the first posterior; generallythere is a

stump

of a vein nearthe origin of the praefurca, -andanindication ofa

second stump

at the inner

end

of the second posterior^cell; discal cell

open

^; the greatcross-vein is a considerable distance before the inner

end

of the discal cell.

Hah. Washington, D

C. ;

Trenton

Falls,

N. Y.

;

South

Caro- lina (Berlin

Museum).

Gen.

XXIV. EMPEDA.

Two

submarginal cells; the first rather short,owing to the shortness andthe oblique direction of the anteriorbranchofthesecondlongitudinal vein; a distinctmarginalcross-veinconnectingthefirstandsecondlongi- tudinalveins is inserted a considerable distancebefore the innerendof thefirstsubmarginalcell^; four posteriorcells; di^alcellclosed oropen;

when

open,it coalesceswith thesecond posterior cell.

Wings

glabrous.

Antennae16(?)-jointed. Tibiaewithout spursat thetip,tarsiwithdistinct empodia.

This

genus

is

undoubtedly

allied to

Goniomyia,

asthe general appearance, the coloring,

and

in part also the venation of the speciesshow. Dr.Sdiiner

(Fauna

Austriaca,Dijytera,II,p.542)

gave

a

wider

definitionto

Goniomyia,

so as to

embrace

this

group

of species also. I think,however,thatitissufficiently distinct, to be introduced as a separate genus, leaving

Goniomyia

with its

formerdefinition (as

adopted by me

in 1859).

JEmpeda

diS'ers

from Goniomyia

in thefollowing characters : 1.

The marginal

cross-vein ispresent; but

owing

to the shortness of the anterior

branch

of the second longitudinal vein, it isnot ^this branch, but the petiole of the first

submarginal

cell,

which

the cross-vein connects with thefirstvein; the cross-veinisthus placed

between

the origin of the third longitudinal vein

and

the fork of the

184

^.

DIPTERA

OF

NORTH AMERICA. [PART

IV.

second,

and

nearer to the former than to the latter.

(Compare

the figures of the

wings

ofthe

European

speciesnuhila

and^ai-a

in

SchummeVs

Beilrage, etc. Tab. II, fig. 4

and

5, which, in regard to the position of the cross-vein, arein perfect

agreement

withtlie

American

species.) 2.

The

auxiliaryvein is longer than in

Goniomyia,

that is, it extends

beyond

the origin of the

second

longitudinal veinto a distance

which

is equalto half the breadth of the wing, or a little shorter; the cross-vein is very near its tip (this, according to the

same

figures of Schuramel, isalsothe casewith the

European

species). 3.

Whenever

the discal cellis open, it coalesces with the second, not

with

the third posterior cell(the latteristhecase in

Goniomyia)

; in other words,it isnot the anterior

branch

of the fourth longitudinal vein, but the posteriorone,

which

is forked (this again is distinctly

mentioned by

Schiner,^{1. c.} p. 544, lines 4

and

14

from

the bottom, for the

European

species,

and

figured

by

Schumrael). 4.

The

forceps of the

male

has a different structure; I

am

unable todescribe it,

not

having

observed it

on any

living specimen, but

even

dry ones

show

plainly that the forceps has a

more

simple structure,

and none

of the

numerous

branches

which

distinguish theforceps of Goniomxjia.

Besides the single

North American

species, described below, three

European

species

undoubtedly

belong here:

Limnobia dihda

Zett. (Schii>er);

Limn,

jlava

Schum.

;

Limn,

^nuhila

Schum.

The name

of this

new genus

is derived

from

liiTtt^ioi, steady, unshaken.

Descriptionofthe species.

I.E. sti^matica,

^{n. sp.}

%

^.

—

Fuscana,halteribuspallidis, alis im- maculatis; celluladiscoidalisaperta,

cum

secundaposterioriconfluens.

Brownish,with pale halteres,immaculatewings,and an open discalcell coalescentwitiithesecondposteriorcell. Long.corp. 0.2.

Dull

brownish

; antenna? black; inthe male, with rather

long

verticils; a sulphur yellow spot

on

the

humeri

^; halteres pale yellow; forceps of the

male

reddish-brown; feet

tawny. Wings

nearly hyaline; veins

brown

;

stigma

very slightly tinged with

brown

; thetipofthe auxiliary veinis nearlyinthe middleofthe distance

between

the origin of the prsefurca

and

the marginal cross-vein; the distance

between

thetip of the firstlongitudinal

CRYPTOLABIS. 185 vein aiKl the tip oftlie anterior branch of the second is distinctly shorter than the distance

between

the tips of both

branches

of the second vein ; third

and

fourth veins

somewhat

con- verging_; discal cell open, confluent with the second posterior cell (for

more

details about the venation

compare

the generic characters).

Hab. Trenton

Falls,

N. Y. A

male

specimen

; another one,

which

isinjured, has only the thorax

and

the

wings

left.

Gen.

XXV. CRYPTOLABIS.

Two

submarginal cells; the inner marginal cell is short and almost tri-

angular(Tab.II,fig.11),owingtothe shortnessandthevery oblique course of the praefurca; the origin of the latter is a littlebeyondthemiddleof thelengthofthewing; four posteriorcells;discalcell open;theposterior branchofthe fourth longitudinal veinisforked.

Wings

glabrous,except an almost microscopic pubescenceinthe apical portion of thewing. An- tennae 16-jointed. Tibice without spurs at the tip; empodia distinct.

Forcepsof the malewith very small hornyappendages; ovipositorofthe femalewithoutanyapparenthornyvalves.

The body

isshort

and

stout; the antenna;, if extended back- wards,

would

not quitereach the root of the

wing;

joints of the flagellum oval, with rather long, verticillate hairs.

Rostrum

short_; palpi with subcylindrical joints of nearly equal length.

Feet

rather short

and

stout, strongly pubescent; those of the intermediate pair

much

shorter than the hind ones; tibise slightly incrassated towardsthetip;

ungues

very small;

empodia

distinct.

Thoracic suture distinct.

Wings

(Tab. II, fig. 11)comparatively short

and

broad; theauxiliary vein

ends

alittle

beyond

the origin of the second longitudinal vein;

the

rather indistinct subcostal cross-vein isat a distancefrom the tipof the auxiliaryvein,

which

isequaltoabout one

and

a half thelengthof thegreatcross-vein

;

owing

to the shortnessof the praefurca, the subcostal cross-vein isa little anteriorto the origin of the latter; thebranches ofthe secondvein

and

the third vein are straight, the

two

latternearly parallel; the veinsseparatingthefirst, second,

and

third posterior cells aregently arcuated; the second submarginal cell is equal in length tothe first posterior cell; the discalcell being open, coa- lesces with the second posterior cell.

The

inner marginal cell (included

between

the praifurca

and

the marginal cross-vein) is

not elongated,as usual,but has the shapeofan almostequilateral