Some Arctiid Structures

OF WASHINGTON. 107

To

_completethisshortreview of theinsectsfoundon_Uniola,itstillre-

mains to be mentioned that the stemsdesertedbythe Mordellistenafre- quentlybecome theabode ofnumerous_specimensofaPtinidbeetleof the genus Hemiptychus,^{the larvaeof}which feed upon ^{the debris left} by^the Mordellistena larva.

Mr. Schwarz made

a

communication

_regarding the correlation in the increase of the

number

of mosquitoes on ^the one side

and

certain species of dragon-flies

on

the other _{side, as} observed

by him

in the

months

of

May

and June,^at Biscayne Bay, ^{in south-} eastern Florida.

The

_followingis an abstract

from

his

remarks

:

Mosquitoes aboundⁱⁿthat sectionof thecountry^atallseasons, butwhen- ever the regular ^tiradewind ceases to blow_theyenormously^{increase in} numbers andbecomea mostserious _pest,which _greatlyinterfereswithall out-door occupations, especiallyⁱⁿthe

hammock

lands. During^suchmos- quito spellsthere isan_equallysudden and great increase ⁱⁿ numbersof certain dragon-flies,andthisisthemoreinteresting because there^isagreat scarcity offresh water in the country^{south of}Miami River. It

may

^be presumed, however,^that most of the dragon-flies come from the Ever- glades ^to the shore ofBiscayne Bay,^a distance ofabout ₇or8 miles.

Three _species of dragon^flies, Celithemis eporina, Libellula auripennis, and

Anax

_/w^5,werethus incrediblyabundantattimes, whiletwoor three others did notparticipate in this increase.

Mr. Schwarz

also mentioneda peculiar habit ⁱⁿ

Danais

bere- nice observed

by him

^at Biscayne Bay, ^Fla.

Whenever

^{the cut}

weeds and

_shrubbery

were burned on

the cleared patches, these butterflies congregated ⁱⁿgreat

numbers on

theheated rocks close to the line of thefire.

Mr. Smith

exhibited aspecimen^of Cicindela Belfragei,

which shows

a curious abnormity ^{in the} shape ^of an acute tubercle

on

the left sideof the prothorax.

Mr. Smith

also called attention to

some

modifications of tarsal structure

among

^{the Arctiidcz.}

He

finds that

some

_{genera, as}

Leucarctia and Ecpantheria,

^{have theclaws cleft to thebase}

others, like

Phragmatobia

and Pyrrharctia, have

them

dentate at the _tip, while in

Spilosoma and Antarctia

^{there is a distinct} long^{tooth at the}middle of the claw.

The

claws are notalways alike

on

all feet.

Sometimes

the claws of fore tarsi only^are toothed, and sometimesallare so in

any

case the anteriorclaws are the ones modified.

What

^{value thischaracter} should have is

yet uncertain.