download pdf

241
Munnoniscus marsupialis, G. 0. Sars.
(PL XOIX, fig. 2.)
Cryptothiria marsupialis, G. O. Sars, Ovei-sigt over Norges Crustaceer I. p. 74, PI. 2. fig.
: Syn Munnoniscus
Sarsii, Giard & Bonnier.
22 23.
Specific Characters. Body of adult female nearly as broad as it is long,
somewhat narrower in front] than behind, and divided behind into two lateral
lobes of somewhat unequal size, the right lobe generally advancing beyond the
left, from which it is defined by a deep and narrow incision, in front only by a
slight sinus; dorsal area comparatively small, diamond-shaped. Younger female
more symmetrical in form, regularly bilobed behind, and obscurely trilobate in
front; dorsal face convex and slightly wrinkled, ventral flattened, with a slight
groove along the middle. Length
of adult female 2 ]
/2 mm. Parasitic on Eurycope
cornuta G. 0. Sars and Ilyarachna longicornis G. 0. Sars.
Remarks. As above mentioned, this is the only species of the genus as
yet known, for the form named by MM. Giard and Bonnier M. Sarsii does not
in reality differ in any respect from the type species, except by its occurrence
on a different species of Munnopsidce. The male and last larval stage I have
not succeeded in finding; but the embryos (see fig. 2 emb.) are fully normal,
exhibiting all the features found in other Epicarida.
Occurrence. I have found this extremely degenerate parasite in the marsu-
pial pouch of 2 different Munnopsidce, viz., Eurycope
cornuta G. 0. Sars and
Ilyarachna longicornis G. 0. Sars, more frequently in the former than in the
latter. In both instances the incubatory lamellae of the host were fully deve-
loped, and the parasite must accordingly have entered the marsupium immediately
after the young of the host had escaped.
Gen. 6. LlriOpSlS, Mac Schultze, 1859.
Syn. : Liriope, Rathke.
Ci-yptothiria, Sp. Bate (part).
Generic Characters. Body of adult female consisting of two very sharply
defined sections connected by a narrow neck, the anterior deeply immerged within
the body of the host, the posterior freely exposed, the former showing
traces of
segmentation, the latter quite simple. No trace of any appendages or affixing
31. Crustacea.