An American species of the genus <I>Caeculus</I>

OF WASHINGTON. 221

tubercles

were

neverbefore

made

use of in systematic

work, and

hefelt sure these

would

be found to be_{of great}taxonomic_signifi cance.

-

Mr. Banks

presented the following paper^:

AN AMERICAN SPECIES OF THE GENUS CiECULUS.

By NATHAN BANKS.

In every

group

^{of animals there are a} few genera having char acters

which

_ally

them

tovarious larger groups, ^{or serve to} con ceal their true relationship. In theAcari there are several such genera,

and

not least interestingof

them

isCaBCulus. Its general appearance ^atonce reminds one of certain Oribatid mites, viz., Nothrus.

And

on a closerexamination one finds several struc tures

which would

confirm thisappearance.

But

there are cer tain characters,

deemed by

acarologists of

much

importance,

which

_place the mite near a quite^different family, the

Trom-

bididas.

These

_important characters are the_palpi,the structureof the coxae,

and

the peculiar eyes.

The

_{eyes are} almost_exactly as in

Trombidium,

an arrangement ^not found elsewhere in the Acari.

But

the dorsal _shields, the rough spinose legs,

and

the large ventral openings ^{are characters} wholly foreign ^to the Trombididae.

The

early writers placed the genus ^{after Oribata,}

and

Gervais suggests ^{that it} has

some

_affinity with Phalangium. ^In 1877 Canestrini and

Fanzago

^{wrote a} paper

on

thegenus

and

erected forita

new

_family,

which

_theyplacedneartheTrombididae. This position ^it has since occupied ^{in all} classifications. Canestrini

and Fanzago

gave ^the genus*^a

new name, Hoplopus

^{; because} theythought Caeculus inappropriate, and called the family

Hop-

lopidas.

But

since

Hoplopus

^isa

synonym,

the familyshould be called Cajculidas.

The

_genus is represented ⁱⁿ southern

Europe

^{and northern} Africa by one species, C. echiuipes. Last _spring

Mr. H. G.

Hubbard

sent

me

a mite taken at

Palm

_Springs, California. It

proves ^to belong ^{to Caeculus,}

and

differs from the _typical

Euro

pean species ⁱⁿ several

minor

particulars.

Caeculus americanus,n. sp.

Length 1.3

mm.

Black,^soft portions rather reddish-brown. Cephalic shieldmorethan twiceaslong^asbroad infront,twiceasbroadbehindas in front, sides sinuate, anglesrounded; from^thefrontmargin^there projects four spatulate ^hairsor_scales; there are two subparallel middlelinesnot reaching ^to the hind margin^; under the hind angles ^{arise a} double tubercle, each bearing an _eye. Anterior shield of the abdomen one-

222 ENTOMOLOGICAL SOCIETY

third broader behind than in front, rather concave _above, traversed byirregularlow _ridges, and two longitudinal lines rathernearer to the lateral margin ^than to the middle. Posterior abdominal shield

much

broader than anterior, ^its front border concave, broadlyroundedbehind, bearingabove twoscale-like hairsonthefrontborder, fourin atransverse linebeyond the middle,and four moreon hind border. Venterwith _largeanal and _genital openings ^close together. Legs very large and stout, first pair longest but plainly shorter than body, ^all roughened and clothed with clavate hairs, two on the front

maginof the anterior trochanters are larger, spatulateand curved. The first leg ^is armed with stouterect, slightlycurved_{spines, longer} than the widthsof the_joints,two on the inner border of femur, three on the inner borderor tibia, five on inner border of metatarsus;

rathersmaller and more curved ones on the loweroutsidemargin^{of these}joints. Palpi not very long, bristly.

Two

_specimens collected by

Mr. H.

G.

Hubbard,

^at

Palm

Springs, California.

BIBLIOGRAPHY.

FIG.16. C<eculusamericamis enlarged. (Original.)

Dufour, ^L. Descript.

and

_figure of Casculus echinipes.

des Sci. Nat.,

XXV,

_{1832, p. 289, pi. 9, figs. 1-3.}

Gervais, P. Apteres, III, p. 260, pi. 38, fig. 5.

Lucas,

H.

_{Explor. Algerie., p. 307, pi. 22,}

fig. i.

Canestrini

&

_Fanzago. Sul. gen. CaBculus, p. 477;

ital., p. 75, pi. 2, fig. ^i.

Berlese,

A.

Acari ital. Prostigmata, pi. 50, ^fasc. 50.

Ann.

Acarof.

-

Mr. O.

F.

Cook

presented the followingpaper^:

NEW DICELLURA.

By ^O.

^F.

^COOK.

The

_genus

_Japyx

_Halliday ^has been recognized* as a distinct order under the above

name. To

the Japygidag ^{is to} be

added

a

new

_family, Projapygidas, founded on

Projapyx

stylifer^^a

new

*Brandtia,p.49,July, 1896. InOctoberof the same_yearMr.

Ashmead

published ^the.nameUratocheliaforthesame_groupinVolumeIIIof these Proceedings, page327.

tSee_plate II,figs. 5a-5d.