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soft metasome of this Crustacean, lying,
as a rule, somewhat diagonally
along the upper face of that part; hence the peculiar twist of its body. The
male is generally found clinging to the left side of the metasome of the female,
or, in younger specimens,
to the ventral face of that division.
Distribution. British Isles (Sp. Bate), Kattegat and Skagerak (Copen-
hagen Mus.), French coast (Hesse).
2. Athelges tenuieaudis, G. 0. Sars, n. sp.
(PI. LXXXIX, fig. 1).
Specific Characters. Body of fully grown female very
like that of the
preceding species, though somewhat more slender, with the anterior incubatory
plates more projecting and expanded in a fan-like manner. Metasome compara-
tively longer and narrower, being abruptly twisted to the left, terminal
piece nearly cylindric in form. Lamellae of pleopoda subequal oblong oval in
shape. -
Body of young female rather slender, claviform,
with the anterior di-
vision of the body rounded oval and perfectly symmetrical, metasome slightly
turned to the left, very slender, cylindric, and much longer than the preceding
part of the body ; terminal piece somewhat flexuous and narrow cylindric in form,
apical tubercles well marked. - - Adult male comparatively less slender than that
of the preceding species, with the metasome abruptly narrowed beyond the base,
and obtusely conical at the tip. Young male, still in the Cryptoniscian stage,
rather broad, depressed, with the segments of mesosome acutely produced late-
rally; uropoda of a similar structure to that in the corresponding stage of Phry.rus
abdominalis. Colour not yet ascertained. Length of fully grown female 11 mm.,
of male 2.20 mm.
Remark*. The fully grown female of this species looks very like that
of A. paguri, and is twisted and deformed in a very similar manner. On a
closer examination, however, the metasome is found to be somewhat more slen-
der, and the terminal piece of a rather different form. In a less advanced
stage, the difference between the two species is much more marked,
the meta-
some in the present species being almost twice as long as in the corresponding
stage of A. paguri, and also much narrower. Its terminal piece, moreover, is
not, as in that species, club-shaped, but narrow cylindric in form. The male, on
the other hand, is comparatively less slender than that of the typejTspecies, and
has the metasome somewhat differently shaped.
Occurrence. Of this form I have myself only found 2 specimens with