114 DIPTERA OF NORTH AMERICA. [PART IV

TOXOURIIINA. 115 opposite the origin of the second vein; section of the second vein, posterior to the small cross-vein, arcuated; thegreatcross- vein is at the

very

basis of the discal cell; the cross-vein sepa- rating the discal from the first basal cell is very oblique;

no

vestige of a stigma (Tab. I, f. 6).

Hah. New

Jersey, in

Jnly

(Cresson^ ; a male and a female specimen.

2.

T. mtllie'bris

^{0. S.} -J,.—Obscure cinerea, fronte latiori, vittis thoracis obscuris,pedibuspallidis, alisimmaculatis.

Darkcinereous, front rather broad, stripes of thethoraxblackish,feetpale tawny,wings immaculate. Long. corp.0.3.

Syn. Toxorrhinamuliehris 0. Sacken,Proc. Phil. Entom. Soc.18G5,p.233.

Head

blackish or

dark

gray; occiput

and

occipital orbits cinereous; antennae

brownish

; basal joints darker

; proboscis pale

brown. Thorax

blackish-gray; the usual three stripes are still darker, almost black; they

occupy

the greater partof the

mesonotum

; the latter shows, especially

on

the sides, ayellowish

bloom

;

metathorax

blackish, witha"gray bloom. Feet,including the coxae,yellowish; tarsiinfuscated

from

thetipofthefirstjoint.

Abdomen

blackish; forceps of the

male

reddish-yellow.

Wings

hyaline;

no

vestige of a

stigma

; costal

and

first longitudinal veins tawny, the other veins darker

brown

; thetip of the aux- iliary veinis

very

slightly

beyond

the origin of the second vein

;

the section of the second vein, posterior tothe small cross-vein, isstrongly arcuated; the cross-veinat the inner endofthe discal cell is very oblique^; the great cross-vein is a little before the discal cell.

Hah.

Princeton, Mass.

(Scudder)

; a single

male

specimen.

This species is distinguished from the preceding

by

its

much

smaller size, itsdarker

and more gray

^coloring,

and

its

compara-

tivelybroaderfront.

Whether

the position of the great cross- vein,

which

in T.

muhebris

is before the discal cell, is also to be reckoned

among

the constant characters of thespecies, isuncer- tain,as I

have

buta singlespecimen.

The

joints of theflagelhini of this species immediately following the stout basal joint, are veryshort

and crowded

together; they are

more

elongated in T.

magna. The

color of the only

specimen

in

my

possession is

somewhat

injured

by

moisture, especially aboutthe head.

116

DIPTERA

OF

NORTH AMERICA. [part

IV.

Gen. IX.

mCRAIVOPTYCHA.

Onesubmarginalcell; four posteriorcells;a discalcell;thefirstlongi- tudinalvein verylong, itstipisnotveryfarbackof thetipof thewing

;

the submarginal and the posterior cells also elongated; a distinctfold, originatingfromaboutthemiddleoj"thesixthlongitudinalvein, runs alongthe middleoftheanalcelltowards the posteriormargin (Tab.I,fig. 8).

Wings

elongated, strongly iridescent; veins pubescent. Feetlong,pilose; tibise without spurs at the tip; erupodia distinct; ungues smooth. Antennae 16-jointed, of moderate length. The forceps ofthe male consists of the usual basal pieces,with claw-shaped or hook-shaped hornyappendages (Tab. Ill, fig.12, one-halfofthe forceps ofD.sobrina; Tab. Ill, fig. 11, forceps of D.nigripes).

Rostrum

short,

epistoma

transverse, stout; lips ratherfleshy

;

palpi short,secondjoint short, stout, thethird a littlelonger,the fourth not

much

longer

than

the third.

Eyes

glabrous, front rather

broad

;

on

the

under

side of thehead, the eyes are con- tiguous.

The

antennae,

when

bent

backwards,

reachthe root of the

wings

in the

male

; they are a littleshorter in the female

;

secondjointstout; fouror five basal joints ofthe flagellum short cylindrical; the following ones.

more

elongated, slightly incras- sated atthe basis; verticilsmoderatelylong. Collare

moderately

developed, the

head

closely applied to it; thoracic suturedeeply

marked. Feet

long, rather stout, pilose;

empodia

large

and

distinct;

no

spurs; theusual excision exists

on

the

under

side

between

the

two

last tarsal jointsin the male.

The appendages

of the

male

forceps of

D.

sohrina are double

on

each side; a horny, pointed,

unguiform

piece,

and

a

more

lamelliform, coria- ceous, curved piece,

with

a brush of short hairs at the tip

;

the forceps of

D.

nigrvpes (Tab. Ill, fig. 11) has a

somewhat

similar structure; only the

horny appendages

are longer

and form

a double curve (for

more

details,

compare

the explana- tion oftheplates atthe

end

ofthisvolume).

Upper

valvesof the ovipositor are of

moderate

length, arcuated,

somewhat

flattened,

and

ratherblunt at the tip.

The wings

(Tab. I, ^fig. 8,

wing

of

D.

sohrina) are elongated

and

comparatively

narrow

; the aux- iliaryvein reachesconsiderably

beyond

the origin of the praefurca,

and

ends in the costa a short distance

beyond

theinner

end

of the submarginal cell; the subcostal cross-veinisclose

by

its tip

;

the firstIsngitudinal vein runs very far

towards

the

apex

of the

wing;

its tip is nearer to this

apex

thanto thetip of theaux-

DICRANOPTYCHA.

117 iliary vein; the marginal cross-vein is

somewhat back

ofthis tip, at a distance whicli is a little shorterthan the great cross-vein_; the stigma is indistinct,

forming an

elongated streak

on

both sides of the first longitudinal vein; the origin ofthe second vein

is before the

middle

of the length ofthe

wing

; the pr^furca,

very

slightly arcuated at its basis, is generally short,

much

less than half the length of the subraarginal cell; this early origin ofthe prnefurca, its shortness,

and

thelengthofthe wing,necessi- tate an unusually long subraarginal cell; its sides (second

and

third veins), are nearlyparallel

and

generally arcuated; the first posterior cell is a little sliorter than the subraarginal; the discal cell has the shapeofa parallelogram; the foldin tlie anal cell is

especially perceptible

when

the

wing

is held against the light; it

assumes

then the

appearance

of a vein,

which

disappears before reachingthe posterior

margin

; thethree last longitudinal veins are nearly straight.

The

venationvaries but little inthe species

which

I

have examined

; the difference principally consists in the length ofthe prrefurca.

The

veins are always finely pubescent

;

thecostaisalso

more

hairythanusual,

and

sometimes,inthe

male

sex, bears aconspicuous fringe of dense

and

comparatively long hairs.

The wings have

a I'ather striking iridescence, which, as inAntocha,

seems due

to the great density

and

minuteness ofthe microscopic

pubescence

of the surface; although transparent, they

have

a dull appearance,

and

are

always

tinged withgrayish or yellowish.

Besidesthe three species described below, I possess one

from

California

and two

occur in

Europe. The

prevailing colors

seem

to be dull grayishor yellowish, without

any

well-marked stripes or bands.

The

presence of crapodia

and

the structure of the

mouth remind

of

Limnophila,

from which, however,

Dicranoptycha

is

abundantly distinguished

by

the

want

of a second subraarginal cell andofspursonthe tibige.

No immediate

relationshipcan yet be pointed out, exceptperhaps the

European genus Orimarga.

The name

ofthisgenus,established

by me

in1859,^isderivedfrom Sixparor, fork,

and

rcrvxr, fold, inallusion tothefold inthe analcell.

Descriptionofthe species.

1.

D. germana

^{0. S.} % and 9^•

—

Fuscano-ochracea^; alis fiilvo- tiuctis,opalizantibus; prsefurcacellulS,discoidalimultolongior.