NO. 13 STAPH YLINIDAE BLACK WELDER 47

Strip anteriorto the sternal suture.

The

lageniform pores are very- abundant, especiallyon the posterolateral portions of the ventral as- pectof eachsternite.

The

paratergites (fig.9 A,^ptt,

E)

are

narrow

longitudinalsclerites onthe dorsal aspectbetweenthetergites and theup-turned edges of thesternites. Thereisoneoneachsideof thefirstabdominaltergite, one on each sideof the second tergite, and

two

oneach side of the segments fromthethird tothe seventh.

The

eighthsegmentalone has no paratergites.

The

first

two

segments have alreadybeen described.

The

paratergitesof the third to the seventhsegmentsareverysimilar in

form

and arrangement throughout.

The

median one is slightly expanded andtruncated anteriorlyand

more

orlesstapering caudally.

The

outer one is rather larger posteriorly but rounded, and tapers

somewhat

anteriorly.

On

the seventhsegmenttheinner paratergiteis

much

^shorter,being only half the usual lengthand

more

sharply taper- ing. All the others are equalinlengthtotherestof the segment.

The

inner paratergite of each segment bears a raised lineor fold {pts) near the anteriorend insucha position as^toappeartobe a continua- tionof thetergalsuture (ts).

The

endoskeleton of the

abdomen

consistschieflyof

narrow

apophy- sesalong themarginsof the segments. Thesearesometimes

known

as plicae,and MacGillivrayhasproposeda systemof

naming

them.

Each

of the dorsal segments

from

the second to the ninth has a narrow

phragma

near the anterior margin which extends along the sides tothe posterior angles excepton the second, eighth, and ninth segments (fig. 5

A).

These phragmata are

marked

externally by sutures (fig. 9

A)

exceptonthe second, eighth, and ninth segments, inwhichthephragmataareatthe anterioredgeof the segment.

Each

spiracle, except those on the eighth segment, has a small roughly circularapophysis onitsentalsurface.

On

thefifthand^sixthsegments thereisaverysmall transverseapophysisjust infrontof themargin.

Theseare apparently not

marked

ontheexterior.

The

tergal or dorsal

member

of each pair of paratergites has a

narrow

apophysis alongthe anteriorend and themedian edge. This

isfound onlyonthe thirdto seventh segments.

The

ventral segments

from

the third to the eighth each have an anterior apophysis similar to the dorsum.

A

transverse posterior apophysisispresentonthe third tosixth sternites.

THE

GENITALIA

The

abdominal segmentsposteriortothe eighth

form

thegenitalia.

Owing

to special modifications, these are very different in the

two

4

48

94 sexes.

The

genitalia of the female (fig.

qB.C)

are comparatively slight modifications of theninthandtenth segments.

The

tergiteof theninthsegment(tt.g)^isthescleritetermedtheproctigerby

Tanner

(1927).

The

anus (mi) is borne not atthe end of this scleritebut onanother lobebeneath this,the dorsal surface of whichrepresents thetenthtergite.

The homology

of the pair of elongatelobes,called paraproctsby Tanner, whichliealong thesidesof the true " proctiger^"

or tenthsegment,are not

known. They

mostlikely are partsof the ninth

tergum

which have

become

separated

from

the tergite.

The

sternum of the ninth segment is represented in the two rectangular sclerites (vlf) meeting along the midline andcalled the valvifersby Tanner. Thesebear a pair of two-segmented appendages

composed

of a basal coxite (cxt) andastylus (sty). Thisinterpretationdiffers

somewhat from

that of Tanner,ashe considered the valviferstobe the basalsegmentof theappendagesof the ninth segment.

The

open- ing of the vulva (vul) is behind (entad) and between the apices of the sternal plates.

The

distal portions of the ninth tergite and the laterallobes,thevalvifers, thecoxites,and ^thestyli are clothedwith rather longbut pale setae.

The

surface of the

membrane

about the vulvaisfinelymuricatewith rather bluntpustules.

The

genitaliaof themale (fig.9

G)

are

much more

highlyspecial- izedor modified than thoseof the female inthisspecies.

The

several sclerites caudad of the eighth segment of the

abdomen

but not ac- tually forming part of the aedeagus have notheretofore been con- sidered as part of the male genitalia. Since they correspond rather closely tothepartsof the ninthsegment inthe female, they are here includedwiththegenitaliaof the male.

The

ninthsegmentappearstobe present as fourdistinct parts.

The

mediandorsalsurface (fig.

9

A,^tt. p) ^isalmostentirelyunsclerotized but bears

numerous

setae. Thisareais

assumed

torepresent the ninth tergite.

On

eachsideisanelongate lobe (vl),heavilysclerotizedand densely clothed withsetae, whichis interpreted as the appendage of theninthsegment, the valvula.

The

sternum isoccupiedbya sagit- tate sclerite(s.9) whichisundoubtedlytheninthsternite. Itisdensely clothed with setae similarly to the valvulae andthe eighth sternite.

The

malegenitaltubeconsistsof astrongmedianlobeanda pair of unitedlaterallobes.

The

medianlobe(fig.

9

G,nil) has a largebulbous base and bears the median orifice (1110) at its distal end.

On

the ventral side at the junction of the bulbous part and the distal tube isthe small median foramen (nif) through which passes the ejacu- latoryduct (ej). Thisduct openstothe exteriorthrough thetip of theflagellum (//), whichis

somewhat

coiled and apparently double

NO. 13

STAPH

YLINIDAE

BLACKWELDER

₄₉

and

projects

somewhat from

^the

median

orifice (mo).

The

internal sac (is) israther largeand nearly encloses the flagellum. Itsventral surface is rather coarsely muricate, whereas the dorsal surface is densely setwith tiny spines or pointed processes.

The

internal sur- facejustbelowthe flagellumatthe point sis sculpturedintominute scalelike protuberances (fig.

9F),

while just dorsalto the flagellum is a small lobe projecting

from

the

median

orifice

and

very densely clothed with long but finehairs or setae.

The

two lateral lobes are unitedonthe ventral aspect except^atthetip.

They

areverynearly as long as the

median

lobeand very^slender,witha smallgroupoflong setaeonthe dorsal^{side at}thetip.

The

outer surface of the aedeagus bears no sculpture or vesti- ture, except for the frequent very minute pores which traverse the integument.

Comparative Morphology

of

the Family

The

following section is intended to give a brief review of the variation within the family of certain of the

more

importantcharac- tersas they arefoundintheseriesof speciesstudied. Therearevery probably

many

further modificationstobe foundinotherspecies,but the present study will serve to

show

the chieftypes and the general trend of variation.

the head

The

headcapsule

shows

a great

many

modificationsinstructure as well as a wide variety of

form

and sculpture.

The

proportions of lengthtobreadtharefoundinallstages

from

2:itoi:2 (figs.10,11).

The

shape may. vary considerably within a single genus or even a single species,orit

may

befairlyconstantina larger group.

The

dorsal surface of the head, or epicranium,is generallynotdi- videdbysutures asin

more

generalizedinsects.

Of

the species studied, only Tachyporus (fig. 10C), Tachinus, and

Erchomus

(all in the tribeTachyporini)

show

anytrace of the anterior part of the coronal suture.

A

few ^specieshave a very short part of the suturevisible atthe posteriormarginof the epicranium. TheseincludePsendopsis, Paedcrus, Lathrotrop'is,Lithocharis, Trachysectus, Pinophiliis,

Xan-

fholinns, Staphylinns, Philonthus, Cafius, Glenus, Acylophorus (fig.

IIG), Qued'ms, Bolitohius (fig. 11F), and Xenodusa.

The

frontal sutures arecompletebetweenthe anteriortentorial pits inalltheTachyporinaestudiedexcept

Hypocyptus

(fig. 10

D)

as well as the Habrocerinae and Oxyporinae.

They

werealso found in this conditionin certain Oxyteliniand Piestini.

The

following are noted

50 94 inthisgroup: Trigonurus (fig.lo

A),

Bled'ms,Aploderus,

Oxyporus

(fig. II D), Hahroccrus, Tachyporus ^(fig.

loC),

Tachinns, Ercho- mus, and BoUtoh'nts (fig. iiF).

However,

in none of these species

Fig. 10.

—

Intrafamily variationintheform andstructureof thedorsal aspectofthehead (continuedonfig.11).

A, Tr'uionuniscrotchi Lee. B, Mlcropcplus punctatus Lee. C, Tachyporus jocosns Say. D, Hypocyptus Jongicorms (Payk.). E, Leptochirus me.vicanus Er. F,Aleocharalata Grav. G, Platystcthus aviericanus Er. H, Stciiitssculp- tilisCsy. I,Protcinuslimbafiis Miikl. _J,Pclccomaimmtcstaceiun (Mann.). K, XenodiisasJiarpiWasm. h. Lori)wta cingulata (Lee).

is there any evidence of the presence, as a sclerite, of the frons.

This sclerite is normally

bounded

laterally and posteriorly by the frontal sutures and anteriorly bythe frontoclypeal or epistomal su-