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flagellum much shorter than the peduncle, and rather thick, being composed, in
female, of 7, in male, of 9 articulations only. Legs in both sexes very strongly
built, those in male having, inside the outer joints, a dense fringe of delicate cilia.
Second pair of pleopoda in male with the stylet reaching beyond the inner plate.
Uropoda rather broad, with the terminal plate blunted at the tip. Colour some-
what variable, more or less dark brownish, with irregular shadows of a darker
hue. Length
of adult female 9 mm., of male 13 mm.
Rfmarl*. There cannot be any doubt that this is the true 7. pclagica
of Leach-, and that the form at first described by H. Rathke as I. Iret'icornis and
subsequently named by him /. torosn, is the very same species. By
this form has generally been regarded as only a variety of I. laltica;
recent authors
but I
believe that in doing so, they cannot have examined the true Leachian species,
which it is impossible to confound with 7. Imlticn. As will appear from the
figures here given, this form is in fact a very distinct and easily recognizable
species, well distinguished in both sexes by its short and stout body,
the small
coxal plates, the short and robust inferior antennae, and the unusually strongly
built legs. Moreover, the terminal segment
rather different from that in the other Norwegian species.
of the metasome exhibits a form
Occurrence. Rathke found this form at Christiansund nmong Hfytihix
growing close to the shore. I have myself taken it in another locality,
viz. out-
side Lillesand. south coast of Norway, where it occurred likewise close to tin-
shore, among alga?.
Distribution. British Isles (Leach. Sp. Bate), coast of France (Bonnier).
3. Idothea granulosa, Rathke.
(I'l. XXXIV, fig. 1.)
Idotlica (jramdosa, Rathke. Beit rage zur Fauna Norwegens, p. 23.
Specific (harnct< >
r$. Body oblong oval, somewhat more than 3 times as long
as it is broad, with the dorsal face distinctly, granular being covered with small de-
pressed pits. Coxal plates comparatively small, not contiguous. Metasome in male
comparatively longer than in female, equalling in length the li posterior segments of
mesosome combined, terminal segment in both sexes considerably attenuated, lan-
ceolate, terminating in a rather prominent conical projection, lateral corners rounded
off. Kves of moderate si/e. Superior antenna1 with the last joint of the peduncle
about the length of the 2nd. Inferior antenna- a little longer than in 7. jtcliujica.
though scarcely reaching to the end of the 2nd segment of mesosome, flagellum
not attaining the length of the peduncle, comparatively narrower than in the said