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ally as regards the oral parts and the incubatory plates. The larva figured at the
bottom of the accompanying plate was taken from the marsupial room of a speci-
men, in which the greater part of the brood had been discharged, so that only a
few larva still remained. On comparing this larva with that from Nansen's Expedi-
tion figured on PI. 94 and adduced to Dajus mysidis, an unmistakable resem-
*
blance between the two will be found to exist, especially as regards the peculiar
structure of the uropoda.
Occurrence. I have found this form only on a single species of deep-
water Mysidse, viz. AmUyops abbreviate^ G. 0. Sars. All the specimens were
found attached to the same place on their hosts, viz., to the dorsal face of the
3rd segment of the metasome, and in all the cases the parasite was found to
turn its head forwards in relation to its host, as shown by fig. X. This is
a rather anomalous position, and MM. Giard and Bonnier are therefore inclined
to believe that my statement about this point might be due to some mistake, and
that the parasite might in reality have had its head turned to the opposite side.
Though none of my specimens are now in their original connection with their hosts,
I must still insist on the correctness of my statement. Nor is such a position
quite exceptional among the Epicarida, for, as stated above, the Micronisci
as a rule occupy a similar position in relation to their hosts, and farther below
a Cryptoniscid will be described, Cyproniscus cypridince, which also, in its fully
grown state, invariably
turns its head to the same side as that of its host.
As to the distribution of the present form. I have found it in two rather
distant localities of the Norwegian coast, viz., at Mosterhavn in the outer part
of the Hardanger Fjord, and at Bejan outside the Trondhjemsfjord. Out of
Norway this form has not yet
been recorded.
Gen. 3. ASpldOphryXUS, G. O. Sars, 1882,
Generic Clwrafh'rs. Body of female shield-like, convex above, concave
below, without any distinct boundary between its chief divisions, and with only
very slight traces of segmentation. Cephalic part projecting
the largely developed, wing-like lateral parts of the mesosome,
in front between
its ventral face
forming a horizontal quadrangular plate denning the very small rounded oral