gle joint,
ending in two large claws. The abdomen consists of ten segments, and in
Campodea along each side is a series of minute, two-jointed appendages
such as have been described in Machilis. These are wanting in Japyx.
None of the species in this family have the body covered with scales.
They are white, with a yellowish tinge.

The more complicated genus of the two is Japyx (Fig. 153, Japyx
solifugus, found under stones in Southern Europe; _a_, the mouth from
beneath, with the maxillae open; _b_, maxilla; _d_, mandible; _c_,
outline of front of head seen from beneath, with the labial palpi in
position) which, as remarked by the late Mr. Haliday (who has published
an elaborate essay on this genus in the Linnaean Transactions, vol. 24,
1864), resembles Forficula in the large forceps attached to its tail. An
American species (J. Saussurii) lives in Mexico, and we look for its
discovery in Texas.

[Illustration: 154. Campodea staphylinus.]

Campodea (C. staphylinus Westw., Fig. 154, enlarged; _a_, mandible; _b_,
maxilla), otherwise closely related, has more rudimentary mouth-parts,
and the abdomen ends in two many jointed appendages.

[Illustration: Fig. 155. Larva of Perla.]

Our common American species of Campodea (C. Americana) lives under
stones in damp places. It is yellowish, about a sixth of an inch in
length, is very agile in its movements, and would easily be mistaken for
a very young Lithobius. A larger species and differing in having longer
antennae, has been found by Mr. C. Cooke in Mammoth Cave, and has been
described in the "American Naturalist" under the name of Campodea
Cookei. Haliday has remarked that this family bears much resemblance to
the Neuropterous larva of Perla (Fig. 155), as previously remarked by
Gervais; and the many points of resemblance of this family and the
Lepismidae to the larval forms of some Neuroptera that are active in the
pupa state (the Pseudoneuroptera of Erichson and other authors) are very
striking. Campodea resembles the earliest larval form of Chloeon, as
figured by Sir John Lubbock, even to the single jointed tarsus; and why
these two Thysanurous families should be removed from the Neuroptera we
are unable, at present, to understand, as to our mind they scarcely
diverge from the Neuropterous type more than the Mallophaga, or biting
lice, from the type of Hemiptera.

Haliday, remarking on the opinion of Linnaeus and Schrank, who referred
Campodea to the old genus P