NO. 13 STAPH YLINIDAE BLACKWELDER

Fig.8.

—

^{Morphology of}thelegs ofCreophilusvillosus (Grav.).

A,ventral aspectoftarsusofprothorax. B, ventral aspectofpretarsusofpro- thorax. C,dorsal aspectoftarsusofprothorax. D,combof setaeandcalcarfrom anteriorsideof tibia ofprothorax. E,combof setaeandcalcarfromposterior side of tibia ofprothorax. F,prothoracicleg. G, trochanterofprothoracicleg.

H,articulations ofbaseofcoxaofprothoracicleg. I,metathoracicleg. _J,claw of metathoracicleg. K, coxa andtrochanterofmesothoracicleg.

38 COLLECTIONS VOL. 94 the coxa.

The

trochanterarticulateswith thecoxa by

means

of

two

ratherindefinitecondyles (a,c,anda,a) which permita dorsoventral

movement

only.

The

distal two-thirds of the exposed surface bears

numerous

moderatelylongsetae, and theareaat s (fig. 8

G)

has a very

few

large pores which are quite distinct

from

the setigerous punctures.

The femur

(fig.

8F)

is thelargest segmentof the leg. Ittapers

somewhat

distad and bears a large tubercle on its ventral proximal margin.

The

proximal end is obliquely truncated and is

immovably

unitedtothetrochanterbyaflatsurface.

The

distalendbears a dorso- ventral groovein which thetibia articulates. This groove is

known

as thegonytheca (gony).

The

proximaldorsal tipforms an acutely roundedprojection which appears to articulate to

some

extent with a socketontheouteredge ofthe coxa.

The

posterior surface of the femuris moderately densely set withsetae,

more

sparsely proximad anddorsad.

The

setaeof the anterior surface are similarly arranged, beingvery densealong the tubercle, very sparse on the basal dorsal part,andentirelylacking

from

a

narrow

stripalong the ventral face, which is outlined onboth the anterior and posterior faces by an ir- regular longitudinalseriesof

more

closelyplacedsetae. Anotherseries, of

more

widelyspaced setae,extends alongthe dorsal faceinto

two

smoothareas.

The

setae are

somewhat

longer and

more

densenear thedorsal apicalmargin and

show some

tendencyto serial arrange-

ment

across the tip.

With

transmitted light one

may

observe the minute poreswhichoccurinclustersof

two

to fiveaboutthebase of eachseta.

The

surfaceisextremelyfinelyandirregularly,butlinearly andlongitudinally, striate ingreatpart.

The

tibiais the fourthsegmentof theleg. In the prothoracic leg (fig.8F, tb)it isshorterthan the

femur

and aboutone-half asthick, expanding slightly toward the apex. It articulates with the femur by

means

ofarounded head onitsproximal end, whichfits intothe grooveorgonythecaof the

femur

(gony) andis held therebya pair ofcondyleson each side. This headis

somewhat

curved towardthe femur,allowing thetibiato lie alongthe ventral edge of the femur atrest.

The

distalendof thetibiaisratherrounded and

membranous.

Itbears the tarsusandthe

two

tibialspurs as well as

numerous

very stoutheavysetaearoundthetip.

The

spurs are

known

as thecalcaria (cal).

They

are inserted within the

membranous

area of thetip, but are apparentlymerely slightly modified setae.

The

largerone is in- serted on the posterior side of the tarsus and the smaller one on the anteriorside,both of

them

slightlyventradof themiddle.

The

tip isnearlycircled by

two

seriesof verylargeand heavy setae,one on

NO. 13

STAPH

YLINIDAE

BLACKWELDER

₃₉ the anteriorand one onthe posteriorface.

Those

of the posteriorseries (fig.8

E)

arelongerand

more

slenderthan those of the anteriorseries (fig.

8D),

but the latter series contains

more

setae (about 12) and extendsfarther across thetip.

The main

part of thetibiabears

two

types of setae.

The

most conspicuous is the large thick and blunt setae similar to those of the terminal series but shorter and some- what

more

regularin outline.

They

occur scattered sparsely on the posterioraspect,therebeingperhaps 15 inall,but there are none on the anterior face.

The

other typeisthe smaller taperingsetaewhich

form

the normalvestiture.

They

are sparseon the posterior aspect, none occurringcloseto theproximal end,and they approximatethe length of the larger terminalseriesonthedistalportion, beinggradu- ally smaller toward the base.

The

anterior aspect and the dorsal portion are clothed with these finer setae similarly to the posterior face, but the ventral aspect of the tibia is very

much more

densely clothed.

The

base of nearlyallof thesesetaeissurrounded byagroup of

two

to four pores as onthe femur, and the anterior face is sup- pliedwithadditional scattered pores.

The

surface of thetibiaisvery minutely transversely strigulose in contrast to the femur, which is longitudinallystriate.

The

tarsus of the prothoracic leg (fig. 8F, tar) is rather loosely unitedtothetibia.

The

latterbears a rather large terminal

membranous

areaintowhichthe basalsegmentof thetarsus,theso-calledmetatarsus, is inserted. There are

two

rather indefinite condyles on the tarsus, oneanteriorand oneposterior,butnodefinitecorrespondingcondyles have been observed onthetibia.

The

tarsus consistsoffivetarsomeres or tarsites, of whichthefirst four are greatlyexpanded into trans- verseplates (fig.8 A, C).

The

^firstand secondareapproximatelythe

same

size, thenext

two

decreasing successively in widthandlength.

On

thedorsalaspecteach of these fourtarsomeresisbroadlyemargi- nate anteriorly, whereas the anterior margin of the ventral side is

expandedinabroad curve forminga largeflatplate.

The

space be- tween the dorsal emargination and the ventral plate is

membranous

andreceivesthebase of thenext segment (fig.8 C).

The

fifthtarso-

mere

iselongate, nearly three times as longas wide,and is inserted

upon

the dorsalsideof theprecedingtarsomeresimilarlytotheothers.

It is expanded rather strongly and regularly toward the apex and

israthercylindrical inform.

On

itsdistalendthefifthtarsomerebears a pair of claws(fig.

8

B,un) and anexpanded

membranous

lobecarry- ing a small ventralplate,theunguitractorplate (iifr).

The

claws (fig.

8_J) are slightly compressed dorsoventrally, rather strongly curved and tapering, and theyarticulatewiththe rounded endof the dorsal

40 94 surface of thelasttarsomere.

From

theproximal endof the migui- tractor plate arisesthe tendon of the retractor muscleof the claws (xt).

The

unguitractorplateisrather quadrate, tapering proximally intothe tendon,andispartly insertedintotheendof thelasttarsomere.

Its distalendis

somewhat

indefinitelyproducedintoan unsclerotized area bearing

two

largesetae. This isthe

empodium.

The

dorsal aspect ofeach tarsomere (fig.8

C)

bears afew^scattered moderately long but fine setae,andthe ventral side of thefifth seg-

ment

is similarly clothed.

The

ventralaspect ofeachof thefirstfour tarsomeres(fig.8

A)

isverydenselysetwithlongfine hairs,whichare absent

from

the basal portion of each tarsomere. These four tarso- meres are thus united intoa singlehairy pad.

The two

setae onthe

empodium

have been called parempodia

(Hayes

and Kearns, 1934) and are stated to arise

from

conspicuoustrichophores on the

empo-

dium.

They

are,however, perfectlynormal setae, anditis doubtful whethertheyhaveany suchsignificanceasisimpliedto them. Their insertionisveryinconspicuous as is usualonsuch lightly sclerotized areas.

The

mesothoraciclegsare longer than the prothoraciclegsbut not quite as long as the metathoracic ones.

As

they are similar to the othersinstructureand general arrangement,they are treated briefly andnot figured completely.

The

coxaof themesothoracic leg (fig. 8

K)

isshorterand ovate.

It isstronglyconvexand

somewhat

excavatedonthe ventral aspectto receive the base of the

femur

at rest.

The

proximal end is slightly produced on the outer side to

form

the coxalcondyle (cxa), which articulateswiththe pleural coxal process.

The

trochantinalarticulation issituatednearthe center of theproximal end andisretractedto

form

a concavitythatreceives the endofthe trochantin.

The

distal endof thecoxa^isdeeplygroovedto receivethe trochanter.

The

anteriorlip of the groove forms a rounded condyle that articulates in a small socket onthe trochanter.

The

ventral sideof the latter is prolonged

proximad

intothecoxa,forminga largemuscleattachment.

The

an- terioraspect of thecoxais

somewhat more

densely clothed than the prothoracic coxa,butthe vestitureispractically restricted totheinner ormesalhalf, onlya very

few

scattered setae occurring on thecon- cavity laterad of theliney.

The

distalendof the posterior aspect also bears a fewsetaesimilarto the anteriorside.

At

thetip of the inner face the ^setae

form

a long dense brush, and the punctures are so closeasto

merge

withoneanother.

The

trochanter is moderately densely set with long setae on the ventral andanterior sides.

Each

of the punctures has one or

more

NO. 13

STAPH

YLINIDAE

BLACKWELDER

4I relativelylargeporesclose to it.

The

posterior face is

more

sparsely puncturedthan theanterior.

The femur

of themesothoraciclegis slightlylonger andconsider- ably thicker than that of the prothorax.

The

anterior aspect bears

numerous

moderately long setaewhichare

much

sparser atthe base and

much

shorter along the dorsal edge.

The

posterior faceisglabrous butis extremely minutelylongitudinally striate.

The

ventralpart of thegonythecabears a fewscatteredshort setae.

The

tibiaof themesothoracic leg is very similarin

form

to that of the prothoracic leg. It is nearly one-half again as long and ex- ceedingly roughlysculptured.

The

terminal

combs

of setae arevery similar,andtheother vestituredifferschiefly inbeing longerand

more

dense.

The

^largeblunt setae are longer and

more

irregular in shape and

much more

abundant.

The

calcaria are similar to those of the metathoracic leg (fig.81),

The

tarsus is almost exactly similar to that of the metathorax

(fig. 81). It is very slightly shorter and bears

more

of the large terminal dorsal setaeon eachtarsomere.

The

metathoracic legs (fig.

81)

are longer and slightly stouter thantheotherlegs,but the sculptureandvestitureare not as evident asoneitherof the^others.

The

coxa(ex)isshortand verytransverse, being rather globular medially with a

narrow

lateral extension that bears the pleuralarticulation (cxa),which is rather indefinitely as- sociated with the tip of theepisternum.

The median

proximal part formsthearticulationwiththemetasternum.

The median

distal part articulateswith the trochanter (tr) by

two

sets of condyles,onean- teriorand oneposterior.

The

anterioraspect is sparselyclothed with moderatelyfinesetaewhich

become

denserandlargertowardthe apex.

Thereisaslightconcavityextendingdiagonally across the coxa

from

the

median

anteriorangleandthisirregular bandisimpunctate.

The

posterior aspect isglabrous except for the

median

and apical areas whichare clothed similarlytoandcontinuouslywiththeanteriorparts.

The

caudal or ventraledge of the transverselateral part is slightly concaveandbearsanirregular

row

of smallsetae.

The

trochanter(fig.81,tr) isratherovalin

form

withitsproximal ventralpartextendedintotheinteriorof thecoxa formuscleattach- ment. It is

immovably

attachedtotheposteriorside of theproximal endof the

femur

as intheotherlegs. Itsanteriorsurfaceismoder- ately closely setwith small setae,

among

whichare a

few

of the tiny pores.

The

posterioraspectis glabrous except for a

few

setaewhich arecontinuedaround

from

the anteriorside.

The femur

of themeta- thoracicleg

(fm)

istaperedtoa blunt pointproximallyandtruncated

42 COLLECTIONS VOL. 94 distally.

The

gonythecais rather broad and extends half

way down

the ventral sideas adistinct groove. This groove bearsanirregular

row

of shortsetae.

The

anterior surface is clothed withmoderately longsetae,rather

more

sparseatthebaseand longeraroundtheapex.

These are also

more

densely placed ventrad along the edge of the ventralgroove.

The

posterior surface (fig.

81)

bears a few small setaealong the borderofthe ventralgroove,andnear theapexafew whichare continued around

from

the anteriorside. There is alsoa series of longer close-set setae along the distal truncated margin, whichiscontinuedontothedorsalmarginalso. Thisposteriorsurface

isalsovery minutelylongitudinallystriate.

The

tibia (fig.81, tb) isratherslender, cylindrical,and

somewhat

regularlyexpanded distad. Itsapexbears acomplete circle of large setaeverysimilartothoseonthe prothoracictibia (figs.8 D,

E)

but thecalcariaare

much

largerand

more

conspicuous.

The

anteriorvesti- ture is rather dense and the setae long. It is

much

denser toward theapexandthedorsum.

The

large thicksetaeaj-e scattered irregu- larly over the surface, there being perhaps lo or 12 present.

The

posteriorsurface(fig.8^I) is

more

sparsely clothedandlacksentirely the largersetaeexceptintheapical series.

There

isa dorsalseriesof four orfive of the larger setae.

The

calcaria are unequal inlength, the posterior being

much

the longer, and nearly as long as the first tarsomere. Theirsurfacehas anirregular scaly appearance.

The

tarsus of the metathoracicleg (fig.81, tar) is nearly as long as thetibia,five-segmentedlikethe others,and verynearlycylindrical.

The

firsttarsomere is elongate, nearly as long as thenext three to- gether, the latter decreasing in length slightly

among

themselves distally.

The

fifth tarsomere is

somewhat

shorter than the first and bears two clawsand the

empodium,

which arevery similar to those of the prothoracic leg (fig.

8B). Each

of thefirst four tarsomeres

is a little

more

extended ventrad than dorsad and therefore is in- serted apparentlyatrifle

more

onthedorsalaspect.

They

are rather densely clothedwith smallsetaeexcept for the base of thedistal four, and the surface of thefirstis roughlysculptured.

The

apex of each tarsomere, particularly ventrally, bears a

number

of very long setae which oftenreachtothe apexof the succeeding tarsomere.

The

last oneis

more

sparselyclothed with the longersetaeand bears the two longsetaeontheempodialendof the unguitractorplate.