NO. 6 GRASSHOPPER ABDOMEN SNODGRASS 79 forward as a hoodlike fold that meets the lobes of the eleventh seg-

ment, and isthen reflected inwardto

form

the posterior wall of the genital

chamber

(fig. 26).

The

genital

chamber

and the contained phallicorgansarethus ordinarilyentirelyconcealedbeneaththetenth

and

eleventh segmentsin front, andthe pallial

hood

behind. If the palliumis pulledback

from

theeleventhsegment^it is tobe seen that the epiphallus occupies an anterior pocket of the genital

chamber

beneaththeventer of the tenthsegment,andthattheaedeagusiscon- tained ina posteriorpouch linedbythe inflected fold of the pallium {Pal'),whichlatter extends inward andventrally to the base of the ventral lobe of theaedeagus {vl).

The

floor of thegenital

chamber

laterallyslopes

downward from

in front (fig. 25A),

where

the epi- phallusisseated

upon

it,tothebase of the inner fold of the pallium, but medially, between the epiphallus

and

the aedeagus, it presents a broad, smooth, roundedsurface (D),the posterior marginof which formsthe basal fold (A, D, hf) overlapping theproximal part of the aedeagus.

The

epiphallus is a large irregular sclerite, consisting of two lateral lobes (D, h, h) connected by an arched bridge {i), and provided with the usual hooked anterior processes _(/)

and

broad, strong posterior processes {k) havingavertical position. Just laterad of the epiphallus, in the wall of the genital chamber, areto be seen the small oval sclerites {g) thatgive insertionto the large retractor muscles {261)

from

thelateralparts of the ninthabdominal tergum.

The

structureof theaedeagusis well

shown

intheprotractedcon- dition (fig. 33 B),ⁱⁿ whichthe organ projects dorsally

from

abasal sheath

formed

of the everted pallium {Pal) andthe basal fold {hf) of the genital

chamber

floor.

The two

parts of the dorsal lobe of the aedeagus (r,

m)

are quitedistinct,the

narrow

distalpart (r), ending inthe smallapical processes {n,p), being exserted

from

between the lobate lateral walls of the proximal part (m).

The

ventral aedeagal lobe {vl) embracesthe dorsal lobe posteriorly,

and

betweenthe

two

isa deepcavity into which opens thevertical slitlike phallotreme in the posterior wall of the dorsal lobe.

The

aedeagal

apodemes

(D,

Apa)

project

downward

and forward

from

the base of the dorsal lobebeneaththe basal fold (B, hf),andtheirproximalpartsare united byawide

zygoma

(D,s) intheunder^sideof the fold (B, s).

The

phallotremeis a deepcleft inthe dorsal lobe of theaedeagus

;

initslateralwallsare the usual

two

pairsofsclerites (fig.25

H,

o,q)

.

The

sclerites of the dorsal (anterior) pairendin the meatus,

where

they are unitedwith eachotherbya transverse bridge {t) \nthedorsal wall of thelatter;the ventral (posterior) scleritesare continuous by

narrow

upcurved

arms

(s) with the lateral plates {n) of the en-

6

8o

SMITHSONIAN MISCELLANEOUS

COLLECTIONS VOL. 94 dophallicbulb.

The

posteriorangle ofeach endophallicplateis

armed

internallyby a free spinelike process (G), below whichthe margin of the plateextends obliquely

downward

and forwardtothebase of thegonoporeprocess (3')-

Between

thegonoporeprocesses, as already shown, liesthe gonopore, or true genital aperture (fig. 33 C, Gpr), by which the ejaculatory sac (fig. 25G,

H,

ejs) communicates with thespermatophoresac {sps) of the endophallus.

Romalea

microptera (Beauvois).

— The

distallobe of theninthster-

num

^{in this species} shuts close against the epiproct and paraprocts, so that the palliumisnotexposed and theend of the

abdomen

hasa

Fig.

A,end floor of view.

E

34.

—

Malegenitalia of Romalea microptera (Cyrtacanthacrinae).

ofabdomen. B,epiphallus,dorsalview. C, epiphallusandaedeaguson genital chamber, lateral view.

,same, dorsal view.

D, aedeagus and endophallus, lateral

truncate

f6rm

(fig. 34 A).

The

epiphallus is deeply sunken in the anteriorendof the genital chamber, andthe basal fold rises steeply against the anterior surface of theaedeagus (C), concealinginostof the basal parts of thelatter.

The

dorsal lobeof the aedeagushas a well-developedcylindrical distalpart (D,r)

from

which project

two

pairsofapicalprocesses {n,p).

The

proximalpart (in) bears a pair of short butverywidelateral

apodemes

(D, E,

Apa). The

endophal- lus is relatively small, but the anterior

apodemes

(iv) of its lateral platesare largeand widely divergent (E).

Schistocercaamcricana (Drury).

—

-The elongate subgenitalplateof theninthabdominalsternumofthisspecieshasabroad, deeply emargi-

NO. 6

GRASSHOPPER ABDOMEN

SNODGRASS

iiateextension projecting farbeyondthe originof the

palhum from

its dorsal lamella (fig.35 A,^B,

IXSL). The

exposedpart of the pallium (Pal) forms a thick, transversely corrugated fold against the para- procts.

When

the tenth andeleventh segments are

removed

(B) the genital

chamber

is exposed

from

above, andthere are to be seen on

itsfloorthephallicstructures lying anteriortothe aedeagus, thelatter beingstillconcealedbeneath thepallialhood.

The

epiphallus consists of largelateral lobes (h, h) connected by a

narrow

medianbridge;

anterior processes are absent, but the posterior processes are present

Fig. 35.

—

Male genitalia of Schlsfoccrca amcricana (Cyrtacanthacrinae).

A, endofabdomen. B,dorsalviewof genitallobeof ninth sternum, pallium, andanteriorpartof genitalchamber,exposed by removal oftenthandeleventh segments. C,phallicorgans, posterior view. D,same,lateralview. E, aedeagus with apodeme, endophallus,and ejaculatory sac. F, endophallus and apex of aedeagus.

inthe

form

of large triangular plates {k, k).

Between

the bases of thelatterthefloorof the genital

chamber

presents adeep transverse groove, the partbehindthegrooveterminatinginthe basal fold {hf).

The

aedeagusis small (C,D,

Aed),

butitsventral lobe {vl) isrela- tively large.

The

principal part of the dorsal lobe is formed of the usualproximal subdivision (D, E,

m),

the distalpart (E, r) being

much

reduced and endingina small spoutlike terminal lobe without apical processes.

The

aedeagal

apodemes

(E,

Apa)

are short but broad at their bases.

The

endophallus (F) has the usual structure, but hascharacteristic features.

The

phallotreme sclerites {o, q) are

82

SMITHSONIAN MISCELLANEOUS

COLLECTIONS VOL. 94