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209
not yet stated. Length of adult female scarcely exceeding ;
male 1 mm.
4 mm. that of
Remarks. This form is evidently distinct from either of the 2 pre-
ceding species, differing, as it does, pronouncedly in both sexes. The specific
name here proposed refers to the poor development of the pleopoda and uropoda.
The latter appendages especially are very small as compared with those in the
2 preceding species.
Occurrence. I have found this form occasionally in the branchial ca-
vity of Galathea intermedia Lilljeborg, taken off the south coast of Norway.
The parasite, when fully grown, causes a very strong and conspicuous tuberosity
on one side of the carapace of the Galathea (see fig. 2 *). I have also re-
ceived the same form from the Copenhagen Museum, likewise infesting that
species
of Galathea.
Distribution. Kattegat. (Copenhagen Mus.).
Gen. 5. AthelgeS, Hesse, 1861.
Phryxus, Rathke (part).
Generic Characters. Body of fully grown female very asymmetrical,
twisted both dorsally and to one (generally the left) side ; body in younger sta-
ges of a rather different appearance, being more symmetrical and of a more or
less pronouncedly club-shaped form. Cephalon small, and withdrawn far
into the mesosome, being only visible in a dorsal view of the animal. Seg-
ments of mesosome in fully grown females distinctly defined only along the middle
of the dorsal face, lateral parts unconnected, narrow, undivided, coxal plates
very small. Metasome abruptly narrowed, without any epimeral plates, the last
2 segments united to a narrow, more or less claviform piece. Antenna? very
small, issuing close together from the extremity of the head. Maxillipeds with-
out any terminal joint. Legs rather robust, and in fully grown specimens pushed
wholly on to the dorsa face of the animal. Incubatory lamellae exceedingly large,
overlapping each other ventrally, the anterior ones produced in front far beyond
the cephalon, and folded in a funnel-shaped manner. Of pleopoda only 4 pairs
present, extended laterally, and each consisting
of pronouncedly branchial structure. Uropoda only present
bercles. Male of normal appearance, having the segments
of a narrow stalk and 2 lamella
Parasitic on Pagurids, and always found clinging to the upper
soft metasome.
27. Crustacea.
as 2 wart-like tu-
of metasome coalesced.
face of their