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with the carpal joint oblong fusiform in outline, propodal joint oval, somewhat
shorter, but scarcely narrower. Uropoda about half as long as the caudal seg-
ment, distal joint scarcely longer than the proximal one, both being clothed with
scattered bristles. Colour pale reddish brown. Length
of adult male 11 mm.
Remarks. As above stated, this remarkable form was detected by my
late father in the year 1860, and was briefly characterised in the above-mentioned
journal. Subsequently a fuller description, accompanied by figures, was given
in his paper on the fauna of the Christiania Fjord inserted in ,,Nyt Magazin for
Naturvidenskaberne". It is much the largest of the Norwegian Munnopsidce.
Occurrence. The species occurs along the whole Norwegian coast, from
the Christiania Fjord to Vadso, in depths ranging from 60 to 400 fathoms. In
some places I have found it in great abundance, especially in the deeper parts
of the Christiania and Trondhjem Fjords, as also off the Lofoten Islands. I have
several times observed it in a living state, and watched its curious movements.
It swims backwards in long, though not particularly rapid bounds, and during
this movement the long inferior antennae and the 3rd and 4th pairs of legs are
extended straight in front. Immediately on reaching the bottom,
the antennae
and legs are spread out laterally, and the animal now moves slowly about in the
ordinary creeping manner. The appendages are extremely fragile
and liable to
be broken off from the body, for which reason it is rather difficult to get specimens
in quite an uninjured state.
Distribution. Skagerak (Meinert), Greenland (Hansen), Spitsbergen (Buch-
holt/), the Barents Sea (Hoek), Franz Josef Land (Heller), the Kara Sea (Hansen),
Arctic America (Miers), Atlantic coast of North America (Harger).
Gen. 2. Ilyaraehna, G. O. Sars, 1863.
Syn : Mcsostenus, G. O. Sars (olim).
'H- Churacterx. Body rather compact, clavate in form, attenuated
behind, with a very strongly marked median constriction. Cephalon very large
and broad, transversely truncated in front, dorsal face evenly vaulted, lateral
parts greatly expanded. The 4 anterior segments of mesosome closely crowded
together, and slightly excavated transversally ; the 3 posterior segments large and
convex above, 5th segment scarcely narrower than the preceding segments, and
deeply emarginated behind. Caudal segment narrow, triangular in form. Superior