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without distinct coxal plates. Metasome comparatively short, with the anterior
segments sometimes coalesced, telson generally well denned, linguiform. Both
pairs of antennae, at least in female, short and subequal in length, originating
close together, the one pair beneath the other. Oral parts modified for perfora-
tion and suction. Legs composed of the normal number of joints,
the basal and
ischial ones being rather slender, and forming together a genicular bend ; 1st pair,
as a rule, much stronger than the others and subcheliform ; the 2 succeeding pairs
likewise subcheliform, but much feebler ; the 4 posterior pairs ambulatory. Pleopoda
chiefly branchial in character, 1st pair large, more or less covering the others.
Uropoda with the outer ramus extending upwards, so as generally
to arch over
the base of the telson. Incubatory pouch apparently not formed by distinctly de-
fined lamellse.
Remarks.- In their general outward appearance, the forms belonging
to this family somewhat recall the Tanaidte, having a similar long
row body, and in some cases, there is even to be found a slight attempt
cheliform structure of the 1st pair of legs. But otherwise,
and nar-
at a
the two families arc-
widely different. The structure of the oral parts would seem to point to a para-
sitic habit, but in none of the forms has the mode of parasitism as yet been
stated. The manner in which the metasome terminates is very peculiar, and un-
like that found in other Isopoda; for the telson is well defined from the last
segment, and more or less strongly deflexed,
whereas the outer ramus of the uro-
poda extends upwards so as to arch over the base of the telson, thereby giving
the caudal fan a somewhat cup-shaped appearance. It is indeed from this
character that the name Anthura, given to the typical genus,
has been derived.
In some of the exotic forms, however, this peculiar formation would appear to
be less pronounced than in the northern forms. Several genera have been esta-
blished in recent times, amounting to about 10 in all. Of these, only 2 are repre-
sented in the fauna of Norway.
Gen. 1. Calathura, Norm. & Stebb., 1886.
c Characters. Body moderately slender, with the 2nd segment of
mcsnsome very movably connected, both with the preceding and succeeding segments,
dorso-lateral carinai in all the segments well marked. Metasome comparatively
short, with the segments not very distinctly defined, though apparently present
in the normal number. Eyes imperfectly developed, or quite wanting. Anteimse
subequal in length, both pairs having the tiagella multi-articulate; the superior