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antennae not quite twice as long as the body, flagellum nearly attaining the length
of the peduncle. 1st pair of legs comparatively short, with the 2 outer joints of
about equal length; 2nd pair densely spinous, with the propodal joint longer than
the carpal one. The 2 succeeding pairs of legs scarcely as long as the body.
Natatory legs less strongly developed than in Ilyarachna, carpal joint
of the 2
anterior pairs narrow cordiform, and scarcely longer than the propodal joint, dac-
tylus rather elongated. Uropoda with the basal part oblong oval, slightly narrowed
distally, and carrying about 12 plumose seta?,
inner, but well defined. Colour greyish white. Length
outer ramus much smaller than the
of adult female 5 mm.
Remarks. This species may be easily recognized from the allied forms
by its short and compact body, and by the very conspicuous spinous whorls
encircling the anterior segments
of the mesosome.
Occurrence. Besides off the Lofoten Islands, where the species was first
discovered, I have met with it occasionally at VadsO,
as also in several localities
on the west coast of Norway (Espevser, Floro, Aalesund, Trondhjem Fjord), the
depth ranging from 100 to 300 fathoms. Out of Norway, it has not yet been
recorded.
Gen. 4. Aspidaraehna, G. o. Sars, n.
Syn: Ilyarachna, G. O. Sars (part).
Generic Characters. Body short and compact, with the 2 divisions of mesosome
very sharply defined, the posterior one being very large, clypeiform, partly projecting
in front over the anterior. Cephalon broad, transverse, evenly convex above,
frontal margin slightly emarginated. Caudal segment triangular, rather broad at
the base. Superior antenme much more fully developed
in male than in female.
Inferior antennae of moderate size. Mandibles very strong, cutting edge undivided,
molar expansion very small, conic, tipped with slender bristles, palp distinct, though
rather feeble. The 4 anterior pairs of legs constructed, on the whole, in a similar
manner to that in the 2 preceding genera, though the 3rd and 4th pairs are not
particularly elongated. Natatory legs very fully developed. Uropoda
tinct rami, as in the genus Echinozonc.
with 2 dis-
Remarks. This genus also is founded upon a species previously referred
by the present author to the genus Ilyarachna. A closer anatomical examination
has also in this instance revealed some peculiar features of apparently generic
value. Thus, the uropoda, as in the genus Echinozone, are distinctly biramous;