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that the antennuiae are provided with 6, instead of 4 sensory filaments. Colour
greyish white, less pellucid than in H, Mengii. Length
of adult female 4 mm.
Remarks. The present species was at first wrongly identified by Mr.
Budde-Lund with H. elegans, Schobl, which is the same as H. Mengii, Zaddach;
hut was subsequently recognised by the same author as a distinct species, and
described under the above name. According to him, the H. Mengii of Dr. Weber
is the present species, and not that of Zaddach. Though very nearly
allied to
that form, it is easily distinguishable from it by the rather different sculpturing
of the dorsal face, and by the complete absence of the 2 conspicuous dorsal pro-
minences occurring in H. Mengii on the 3rd segment
also grows to a rather larger size.
of the metasome. It
Occurrence. I have found this form in great abundance in 2 places in
the neighbourhood of Christiania, both located in the so-called Ladegaardso. It
occurred here in loose mould beneath leaves and decaying pieces of wood. I have
also received some few specimens of this form from conservator Storm, who col-
lected them in the neighbourhood of Trondhjem. In habits, it exactly agrees
with H. Mengii.
Distribution. Denmark, Holland.
Fam. 3. Oniscidae.
Characters. Body oval or oblong, with the lateral parts of the segments
more or less expanded. Metasome with the 2 anterior segments rather small,
and having the epimeral plates concealed; last segment much narrower than the
preceding ones, and conically produced at the end. Eyes generally well developed,
compound. Antennuiae very small, with the apical sensory appendages short,
papilliform. Antennae, as a rule, slender, with the flagellum pauciarticulate.
Buccal mass not very prominent below. Mandibles with the cutting part highly
chitinized and, as usual, composed of 2 superposed dentate lamellae, behind which
is a membranous hairy lappet and a varying number of penicils, molar expan-
sion obsolete, without any triturating surface, it being replaced by a brush-like
recurved seta. Anterior maxillae with the outer masticatory lobe very strong and
coarsely spinous at the tip, inner lobe much narrower and provided with only 2
hairy bristles. Posterior maxillae distinctly bilobed at the tip, and having the
outer edge angularly produced near the base. Maxillipeds with the basal part
22 Crustacea.