indicating its former separation in embryonic
life into a pair of appendages. The labial palpi are three-jointed, the
joints being broad, and in life directed backwards instead of forwards
as in the higher insects.

There are five American species of the genus Lepisma in the Museum of
the Peabody Academy. Besides the common L. saccharina? there are four
undescribed species; one found about out-houses and cellars, and the
heat-loving form, perhaps an imported, species, found in a kitchen in
Salem, and apparently allied to the L. thermophila Lucas, of houses in
Brest, France; and lastly two allied forms, one from Key West, and
another from Polvon, Western Nicaragua, collected by Mr. McNiel. The
last three species are beautifully ornamented with finely spinulated
hairs arranged in tufts on the head; while the sides of the body, and
edges of the basal joints of the legs are fringed with them.

The interesting genus Nicoletia stands at the bottom of the group. It
has the long, linear, scaleless body of Campodea, in the family below,
but the head and its appendages are like Lepisma, the maxillary palpi
being five-jointed, and the labial palpi four-jointed. The eyes are
simple, arranged in a row of seven on each side of the head. The abdomen
ends in three long and many jointed stylets, and there are the usual
"false branchial feet" along each side of the abdomen. There are two
European species which occur in greenhouses. No species have yet been
found in America.

[Illustration: 153. Japyx solifugus.]

The next family of Thysanura is the Campodeae, comprising the two genera
Campodea and Japyx. These insects are much smaller than the Lepismidae,
and in some respects are intermediate between that family and the
Poduridae (including the Smynthuridae).

In this family the body is long and slender, and the segments much alike
in size. There is a pair of spiracles on each thoracic ring. The
mandibles are long and slender, ending in three or four teeth, and with
the other appendages of the mouth are concealed within the head, "only
the tips of the palpi (and of the maxillae when these are opened)
projecting a very little beyond the rounded entire margin of the
epistoma," according to Haliday. The maxillae are comb-shaped, due to the
four slender, minutely ciliated spines placed within the outer tooth.
The labium in Japyx is four-lobed and bears a small two-jointed palpus.
The legs are five-jointed, the tarsi consisting of a sin