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89
Mundarea og i Midten endog delvis griber over hinanden
(se Fig. 2). De udspringer vidt adskilte nær Sidekanterne
af Hovedsegmentet (se Fig. 3) og bestaar kun af 2 tydelige
Segmenter. Det yderste at disse er ganske lidet og af oval
Form. hvorimod det 1ste er overordentlig stort, dannende
en bred hvælvet Plade af afrundet triangulær Fonn og langs
den indre stærkt buede Kand forsynet med en regelmæssig
Kad af Fjærbørster. I Midten af Pladen tindes 3 meget
ioinefaldende kalkagtige Concretioner, der giver disse Plader
en betydelig Grad af Fasthed. De her omhandlede Lemmer
maa egentlig, som Prf. Dolirn rigtigt bemærker, betragtes
som et eiendommeligt modificeret Fodpar. tilhørende det
rudimentære mellem Hovedet og Kroppen beliggende
Segment. Da de imidlertid saavel hvad Bygning som Stilling
angaar nærmest slutter sig til Mundpartiet, kan de passende
benævnes accessoriske Kjævefødder.
Af egentlige Fødder findes som hos de øvrige Arter
af Slægten kun ft Par. Disse er (Fig. 9) af kraftig
Bygning. tæt besatte med lange Borster og delvis med grove
Tænder. Af de 5 Led er det 1ste størst og omtrent saa
langt som de 3 følgende tilsammen. Sidste Led danner med
det foregaaende en meget bevægelig Articulation og bærer
i Spidsen en kraftig, krummet Klo.
Det enkle Kjønsvedhæng, der er beliggende (se Fig. 2)
paa Yentralsiden ved Enden af Forkroppen og støttet af
en smal Chitinliste. er meget lidet, neppe fremragende.
Bagkroppens Buglemmer (Fig. 10) bestaar af en kort
Basaldel og 2 smalt tungeformige Grene, hvoraf den indre
er længst. Begge Grene mangler ethvert Spor af Borster,
og disse Lemmer kan følgelig heller ikke fungere som
Svømuie-redskaber. hvorimod Structural af Endepladerne snarere
synes at antyde, at de staar i Respirationens Tjeneste.
Halevedhængene (Fig. 11) danner som hos de øvrige
til denne Gruppe horende Former en fuldstændig Halevifte.
Det midterste Halevedhæng, der egentlig forestiller
sidste Bagkropssegment, er omtrent saa langt som de 4
foregaaende Segmenter tilsammen og ved Basis ligesaa bredt
som disse; den ydre Del er imidlertid meget smal, næsten
lancetdannet med stump tilspidset Ende. Langs Kanterne
ligesom paa den øvre Flade tindes talrige Smaapigge;
derimod mangler de sædvanlige Endebørster.
De ydre Halevedhæng er adskilligt kortere end det
midterste, til hvis Basis de er indleddede. og bestaar af en
kort. men bred Basaldel. der indad gaar ud i en
tunge-formig Flig, og 2 smalt ovale Endeplader, hvoraf den indre
er lidt større end den ydre. Begge Plader viser i Kanterne
en 1 lel uregelmæssige tandformige Fremspring og er desuden
mod Enden i den indre Kant forsynede med nogle tynde
cilierede Børster, hvis Antal er storst paa den indre Plade.
Farven er hvidagtig med et tydeligt blaaligt Skjær.
De blødere hudagtige Partier mellem Segmenterne og paa
Yentralsiden viser en dyb mørkeviolet Farvetone.
Længden gaar op til fulde 12""". og den er saaledes
lien norske Norclhavsexnerfitinn. fi. O. Sars: Crustacea.
buccal area, and in the middle even overlapping each other
(see fig. 2). They take their origin, widely apart, in close
proximity to the lateral margins of the cephalic segment
(see fig. 3). and consist of. only 2 distinct segments, ti.e
outermost quite small and oval in form, whereas the other
is exceedingly large, constituting a broad, arcuate plate,
rounded-triangular, and furnished along its inner,
exceedingly vaulted margin with a regular series of plumose bristles.
In the middle of the plate, occur 3 very conspicuous
calcareous concretions, that give to these plates considerable
firmness. The appendages treated of here must. too. strictly,
as Professor Dohrn with just appreciation observes, be regarded
as a peculiar, modified pair of legs, belonging to the rudimentary
segment, placed between the head and the first free segment.
Meanwhile, since, as regards alike their structure and their
position, they approximate closest the buccal region, they
may not improperly he termed accessory maxillipeds.
Of legs, in a strict sense, there occur, as in the other
species of the genus, only 5 pairs. These are (fig. 9) powerful
in structure, closely beset with long bristles, and furnished
in places with coarse teeth. Of the ft joints, the 1st is the
largest, and about as long as the following 3 taken together.
The last joint constitutes, along with the preceding one.
a very mobile articulation, and bears at the point a. powre: ful.
curving claw.
The simple sexual appendix placed (see fig. 2) oil the
ventral side, at the extremity of the anterior division, and
strengthened by a slender chitinous fillet, is exceedingly
small, and projects but very slightly.
The pleopoda (fig. 10) consist of a short basal portion
and 2 slender, linguiform branches. On neither of the branches
cail a trace of bristles be detected; and hence, too. these
appendices, are unadapted to perform the function of natatory
organs ; nay. judging from the structure of the terminal plates,
they would rather appear promotive of respiration.
The caudal appendages (fig. 11) form, as in the other
species belonging to this group, a true caudal fan.
The median caudal plate, representing, strictly, the last
abdominal segment, is about as long as the 4 preceding segments
taken together, and at the base equal in breadth to the latter:
the outer portion, however, is exceedingly narrow, almost
lanceolate, with an obtusely pointed extremity. Along the
margins, as also on the upper surface, occur numerous
minute spikes, whereas the usual terminal bristles are wanting.
The outer caudal appendages are a good deal shorter
than the telson, to the base of which they are jointed,
and consist of a short and broad basal portion, jutting out
inward as a linguiform lappet, and 2 slenderly ovate
terminal plates, of which the inner is a trifle larger than the
outer. Both plates exhibit along the margins a number of
dentiform projections, and, moreover, are furnished toward
the extremity, on the inner margin, with a few slender
ciliated bristles, greatest in number on the inner plate.
Colour whitish, with a distinct shade of blue. The
softer cutaneous parts between the segments and on the
ventral side have a deep, dark-violet tinge.
Length reaching fully 12"™; hence, this animal is
12
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