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01
Nedentil afsluttes Næbbet med et Par noget mere
complicerede Munddele (Fig. 18). der forestiller de
egentlige Kjævefødder. De er ligesom de ovenfor omtalte
Munddele rettede lige fortil og dækker disse mere eller mindre
fuldstændigt nedentil (se Fig. 14). Man kan paa dem
adskille en i 4 utydelige Segmenter afdelt Stamme eller
Basaldel. der fortil gaar ud i en dolkformig, i den indre Kant
fint tandet Fortsats (Tyggelap). og en til den ydre Side af
denne sidste fæstet enleddet og med korte Borster besat
Endedel eller Palpe, der kun lidet overrager hin Fortsats.
Bag Næbbet er til Hovedsegmentets Underside fæstet
(se Fig. 14) et Par Lemmer, der aabenbart svarer til de
operkelformige accessoriske Kjævefødder hos Hannen, men
som her er udviklede paa en helt anden Maade, nemlig til
kraftige Fastklamringsredskaber.
Af Fonn er de (Fig. 19) cylindriske og noget Sformigt
bøiede samt bestaar af 6 Led. hvoraf de bagerste paa den
indre Side viser et Antal af skarpe chitinøse Tværfolder.
Sidste Led er omformet til en overordentlig kraftig
hage-fonnigt boiet Klo. hvis ydre Del er af særdeles fast
Consi-stens og sylformigt tilspidset.
De egentlige Fodder (Fig. 20) stemmer i sin Bygning
fuldkommen overens med samme hos Hannen, dog med den
Forskjel, at de ganske mangler de knudeformige Tænder,
hvormed de ydre Led hos hin er bevæbnede, ligesom ogsaa
Børstebesætuingen er langt sparsommere.
Bagkroppens Bugleimuer (Fig. 21) er uddannede til
vel udviklede Svømmeredskaber, idet de 2 ovale Endeplader
i Spidsen er forsynede med lange cilierede Svømmebørster.
Haleviften (Fig. 22) er vistnok i Hovedsagen af samme
Bygning som hos Hannen, men viser dog nogle mindre
Dif-ferentser. Den midterste Haleplade er saaledes noget mindre
indknebet i sit ydre Parti, og paa den stumpt tilrundede
Spids bemærkes et lidet mediant Indsnit, fra hvis Bund 2
korte Borster rager frem. De ydre Halevedhængs
Endeplader er forholdsvis noget bredere end samme hos Hannen
og de paa dem fæstede Borster stærkere udviklede.
Farven er ensformig hvid og noget gjennemsigtige
uden Spor af nogen Pigmentering.
Længden af de største Larver er 10""", af de mindste
erholdte 5.80"™.
Forekomst og Udbredning. Nærværende
eiendommelige Art forekommer, som det synes, ikke saa ganske sjeldent
paa de store Dyb i den kolde Area. Vi har Exemplarer
fra ikke mindre end 7 forskjellige Stationer. Dybden fra
658 til 1215 Favne. De allerfleste indsamlede Exemplarer
var fuldt udviklede Hanner: derimod fandtes ingen
fuld-voxen Hun og kun nogle faa Larver. Disse sidste lever
rimeligvis parasitisk paa Dybvandsfiske eller andre større
Dybvandsdyr.
Below, the beak is bounded by a pair of somewhat
more complicated oral appendages (fig. 18). representing the
true maxillipeds. They have, like the oral appendages
spoken of above, a straight, anterior direction, covering the
latter, more or less completely, below (see fig. 14). On the
appendages may be distinguished a stem, or basal part,
divided into 4 indistinct segments, that, anteriorly, jut out
as a dagger-shaped, on the inner margin finely dentate,
projection (masticatory lobe), and. attached to the outer
side of this projection, a one-jointed terminal portion, or
palp, beset with short bristles, reaching but slightly beyond
the said projection.
Posterior to the beak, are attached on the under
surface of the cephalic segment (see fig. 14) a pair of
appendages, evidently corresponding to the operculiform accessory
maxillipeds in the male, but here, however, developed for a
widely different purpose, viz. to serve as powerful prehensile
organs.
They are cylindric and somewhat S-shaped in form,
and consist of 6 joints, of which the hindermost on the
inner side exhibits a number of sharp-edged, cbitinous.
transverse folds. The last joint is transformed into a remarkably
powerful, hook-shaped claw, the outer portion of which is
exceedingly firm in consistence, and produced to an
awl-shaped point.
The true legs (fig. 20) agree completely in
structure with those of the male, saving however the total
absence of tuberculiform teeth, with which the outer joints
in the latter are armed, as also a much less abundant
supply of bristles.
The pleopoda (fig. 21) are developed as fully efficient
natatory organs, the 2 ovate terminal plates being furnished
at the point with long, ciliated natatory bristles.
The caudal fan (fig. 22) is indeed essentially of the
same structure as that in the male, but exhibits however
a few minor points of difference. The median caudal plate
is. for example, somewhat less constricted in its outer
portion. and. at the obtusely rounded point, occurs a small
median incision, from the bottom of which project 2 short
bristles. The terminal plates of the outer caudal
appendages are comparatively somewhat broader than those in
the male, and the bristles attached to them more fully
developed.
Colour a uniform white and semi-translucent, without
a trace of pigment.
Length of the largest specimens of larvæ collected
10""". of the smallest 5.80"1"’.
Occurrence and Distribution. — The present
peculiar species occurs, it would seem, not so very rarely,
throughout the great depths of the cold area. We obtained
examples at not less than 7 different Stations, in depths
ranging from 658 to 1215 fathoms. Most of the specimens
collected were fully developed males, no full-grown female
having been taken and but very few larvæ. The latter
probably exist as parasites on deep-sea fishes or other large
deep-sea animals.
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