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4. Poreellio Rathkei, Brandt.
(PI. LXXIX, fig. 1.)
Poreellio Rathkei, Brandt, Consp monogr. Crust. Isop. terrestr. p. 15. fig. 10.
Syn : Poreellio ferrugineus, Brandt.
trilineatus, Koch.
trivittatus, Lereb.
tetramoerus, Sclmitzl.
striatus, Schnitzl.
syfaestris, Schobl.
Specific Characters. Body oval, somewhat broader in female than in
male, dorsal face rather convex and slightly tuberculated. Cephalon
with the
lateral lobes well developed, rounded, frontal lobe short, obtusely triangular.
Side-plates of mesosorne of moderate size, subcontiguous, with the posterior cor-
ners obtusely acuminate. Metasome scarcely attaining l
/4, of the length of the
body, epimeral plates of 3rd to 5th segments well developed, recurved; last seg-
ment subtriangular, outer part acutely produced and plane above. Antennae rather
slender, nearly attaining half the length of the body, flagellum about the length
of the last peduncular joint, and having its proximal joint somewhat shorter
than the distal one. Last pair of legs in male stronger than in female,
with the
carpal joint remarkably dilated near the base. Opercular plates of all the pleo-
poda with air-cavities. Uropoda with the outer ramus broadly lanceolate, inner
extending considerably beyond the last caudal segment. Colour of dorsal face
somewhat variable, being in female, as a rule, lighter than in male, with irre-
gular dark patches intermingled with some of a ferruginous hue, and more ge-
nerally exhibiting a row of more or less distinct whitish patches
on each side of
the mesosome, at the base of the side-plates. Colour of male specimens generally
dark slaty grey, with 3 longitudinal rows of whitish patches on the mesosome,
the one median, the 2 other sublateral, and between these rows on each segment
an assemblage of light, wavy stripes. Length of adult female 12 mm.
Remarks. This species was first described under the above name by
Brandt, but has subsequently been recorded under several other names, that
proposed by Koch, trilineatus, having been more generally used. It may be
distinguished from the preceding species by its comparatively convex body and
the mutual longitudinal relation between the 2 articulations of the antennal fla-
gellum. The colour, especially of female specimens, is rather variable, and has
occasioned the establishment of several spurious species. In some cases it even
changes to a rather uniformly light ferruginous hue, with scarcely any trace of the
characteristic sublateral row of light patches. More generally, however, these