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occurrence on the following 4 species of this genus has been proved E.
ptjgmcea, serrata, and microplith alma. I have, moreover, found it on Parcrythrops
obcsa, and in a single case also on Jfy*idop*ix (lldi'lphij*. I have carefully compared
specimens from all these different hosts, and have convinced myself that they all
belong to one and the same species. The mode of affixion of the parasite is rather
peculiar. As shown by the figure at the bottom of PI. 96, it covers the
dorsal face of the carapace of its host like a mantle, invariably turning its head
backwards in relation to its host. The exact place where it attaches itself was
not formerly sufficiently determined by me, but I am now fully able to
confirm the statements of MM. Giard and Bonnier on this point. It is, in-
deed, the posterior incurved edge of the carapace, which exhibits the point of
affixion for the parasite, not, as formerly supposed, the dorsal face of the last
free segment of the mesosome. In one case only
have I found it attached^ in a
very different manner, viz., to the left peduncle of the superior antennrc in a
specimen of >
il///*/r7o/W,s
didelphys. The male, as above stated,
is found within
the ventral hollow of the caudal part of the female, and is generally curled up
almost in a circle, always clinging to the above-mentioned fleshy cord issuing
from the genital region of the female.
Out of Norway, this form has not yet been recorded, for the specimen
examined by MM. Giard and Bonnier was found on an Enjthrops microptlialma
taken off the Norwegian coast by the Rev. A. M. Norman.
Fam. 3. Cryptoniscidae.
Characters. Body of adult female reduced to a simple
sac filled with
ova, though sometimes exhibiting slight traces of segmentation, but without any
true limbs. Last larval stage resembling in its outward appearance
that of the
Bopyridce and Dajidce. Antennulse with 2 flagella, and having the basal joint
lamellarly expanded behind, the expansion being more generally divided
into coarse teeth. Antennal flagellum 5-articulate. Oral cone simple, without
any sucking disc. Coxal plates generally closely pectinate. The 2 first pairs
of legs subequal, and much shorter and thicker than the others, which, as
a rule, are very slender, with long setiform dactyli. Pleopoda with both
rami well developed. Uropoda with the outer ramus, as a rule, much