- Project Runeberg -  Den Norske Nordhavs-expedition 1876-1878 / The Norwegian North-Atlantic Expedition 1876-1878 / 6. Bind /
60

(1880-1901)
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60

De ydre Halevedhæng (Fig. 19) har Eudepladerne
temmelig store og brede. Den indre er omtrent ’/i kortere
end den ydre og lancetformig tilspidset samt viser ved Basis
kun ell yderst svag. neppe mærkelig Antydning til det for
Familien eharacteristiske Høreapparat. Den ydre Plade er
af aflang oval Form og viser i den ydre Kaut nærmere
Basis en liden med to Torner bevæbnet Afsats; foran denne
er den ydre Kant ganske glat. medens disse Plader forøvrigt
er rundtom borstebesatte.

Hannen (Fig. 3) er adskilligt større og kraftigere
bvgget end Hunnen og desuden let kjendeligt fra samme
ved de tydeligt udprægede secundære Kjonscharacterer.

lste Par Føleres Skaft (se’ flg. 20) er saaledes
betydelig tykkere og har ved Enden under Svøberne det
sædvanlige haarede Appendix, der dog lier er særdeles kort.
knudeformigt og næsten ganske skjult af eller ligesom
indsænket i en fra Skaftet udgaaende Hudduplicatur.

Svømmegrenene paa Kjævefodderne og de egentlige
Fodder er (se Fig. 3) forholdsvis endnu stærkere udviklede
end hos Hunnen, med Basaldelen bredere og stærkere
muskuløs.

Ved Basis af sidste Fodpar bemærkes de ydre
Kjøns-vedhæng i Form af to cylindriske, noget fortil krummede
og i Spidsen med stive Borster besatte Lapper.

Bagkroppen er forholdsvis kraftigere bygget end hos
Hunnen, og dens Buglemmer samtlige udviklede til mægtige
Svømmeredskaber, med bred muskuløs Basaldel og særdeles
lange, mangeleddede Endegrene. Den indre Gren er her
paa alle Par, ogsaa paa lste (Fig. 21), af ens Udseende.
Den er kjendeligt kortere end den ydre og danner ved Basis
en oval, med nogle faa fine Borster besat pladeformig
Ud-vidning. Den ydre Gren paa 2det Par (Fig. 22) er af
enorm Længde og delt i ikke mindre end 38 Led. hvoraf
de ydre. istedetfor Fjærbørster, er forsynede med korte
simple Torner.

Farven saavel af Han som Hun er i levende Tilstand
temmelig uniform lyserod eller kjødrod. Da imidlertid
Legemet er temmelig gjennemsigtigt, skinner enkelte af de
indre Dele og navnlig den store med mørkerødt Indhold
fyldte Mave, igjennem .Integumenterne.

Nærværende Art opnaar en for en Myside colossal
Størrelse, idet Hunnen har en Længde af 64™m, medens
Hannen bliver endnu adskilligt længere, nemlig indtil 70"™.

Forekomst. Fem mere eller mindre fuldstændige
Exemplarer af denne mærkelige Fonn blev under
Expedi-tionens sidste Togt optaget ved Hjælp af Trawlnettet fra
det enorme I)yb af 1110 Favne i Havet NV. af [Finmarken
(Ståt. 295), og i det selvsamme overordentlig righoldige
Kast, der blandt mange andre interessante Ting ogsaa bragte
op det i det foregaaende omtalte Exemplar af den
eiendommelige Mysideform, Pseudomysis abyssi, ligesom ogsaa
de 4 pragtfulde Exemplarer af Bytliocaris leucopis.

The outer caudal appendages (fig. 19) have the terminal
plates comparatively large and broad. The inner is about
one-fourth shorter than the outer, and lanceolate, exhibiting
at the base an exceedingly laint, scarcely perceptible
indication of the auditory apparatus distinguishing the family.
The outer plate is oblongo-oval in form, and bears on the
outer margin, near the base, a small shelf, armed with two
spines; anterior to this shelf, the outer margin is quite
smooth, whereas the plates are elsewhere beset with bristles
round the edges.

The male (fig. 3) is considerably larger and more
powerful in structure than the female, aud. moreover, may
be readily distinguished from the latter by reason of its
prominent secondary sexual characters.

Thus, the peduncle of the 1 st pair of antennæ (see fig. 20)
is considerably thicker, and has at the extremity the usual
hirsute appendix, which, however, is exceedingly short,
tuber-culiform. and almost entirely concealed by, or rather sunk into,
a thick integumental duplicators issuing from the peduncle.

The natatory branches on the maxillipeds and the true
legs (see fig. 3) exhibit comparatively a still more powerful
development than in the female, having the basal part broader
and more prominently muscular.

At the base of the last pair of legs, are seen the
outer sexual appendages, having the form of two cylindrical,
somewhat anteriorly curved lobes, armed at the point with
stiff bristles.

The posterior division of the body is comparatively
more robust in structure than in the female, and has all of
its limbs developed as powerful natatory organs, with a
broad, muscular basal part and exceedingly long,
multi-articulate terminal branches. The inner branch on all the
pairs, also the 1st (fig. 21). is uniform in appearance. It is
appreciably shorter than the outer, and exhibits at the base an
oval, lamelliform dilatation, beset with a few slender bristles.
The outer branch on the 2nd pair (fig. 22) is of prodigious
length, and divided into not less than 38 articulations, of
which the outer, instead of having plumose bristles, are
furnished with short, simple spines.

The colour, both of the male and female, in a living
state, is a comparatively uniform light-red, or pink. The
body, however, being well-nigh translucent, some few of
the inner parts, and more especially the large stomach,
filled with a dark-red substance, are seen shining through
the integuments.

The present species attains, for a Mysidian. a colossal
size, the female reaching a length of 64’"™. while the male
has a still greater, viz. 70°"".

Occurrence. Five more or less perfect specimens
of this striking form came up in the trawl, on the last
cruise of the Expedition, from the prodigious depth of 1110
fathoms, in the open sea, north-west of Finmark (Ståt.
295), and in the same remarkably rich haul that, among
other interesting objects, also brought to light the previously
recorded specimen of the characteristic Mysidian, Pseudomysis
abyssi. along with 4 magnificent specimens of Bytliocaris
leucopis.

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