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Fam. Sipvuicixlid.se., Baird.
Fam. Sipunculidæ, Baird.
Phascolosoma Lilljeborgii, n. sp. •
Tab. I., Fi». 1—4.
Hele Legemets Længde udgjør paa de største
Exemplarer 80mm. Kroppen, Fig. 1, a, der er cylindrisk, 40"""
lang, 2mm tyk, med en lidt konisk tilspidset Bagende,
haien glat perlemorglindsende, næsten vandklar Hud, som kun
sparsomt er besat med Papiller, der ere saa smaa, at de
van-skeligen kunne sees ’med stærk Loupe, dog staa disse
Papiller noget tættere mod Snabelens Grund og paa den
bagerste Del af Kroppen.
Snabelen, Fig. 1, b, som neppe kan trækkes
fuldkommen ind i Kroppen, er 40""" lang, ligeledes glat,
perlemorglindsende, forsynet med mere tætstaaende yderst smaa
Papiller, og har paa Enden en Krands af 8—10 korte,
temmelig brede Tentakler, Fig. 1, c, der- omgiver den runde
Mundaabniug.
Analaabningen rund ved Snabelens Grund, Fig. 1, d.
Huden dannes af et meget tykt, finstribet Chitinlag
(Cutieula),’ Fig. 3, a, 4, a, indenfor hvilket Epithelet (Matrix)
findes, Fig. 3, b, 4, b, der bestaar af et Lag temmelig store
Cylinderceller.
I Epithellaget sees fornemmelig paa Snabelen en
Mængde Kjertier, som have en bred Grunddel, Fig. 3, c,
4, c, og en afsmalnende Udførselskanal, Fig. 3, d, 4, d, der
gaar igjennem den tykke chitinøse Cutieula, paa hvis
Overflade den aabner sig i en tragtformig Fordybning, Fig. 3, e,
4, e. Kjertelen dannes af en temmelig tynd
Bindevævs-kapsel, Fig. 3, /, der paa den indvendige Flade er
beklædt med Epithel, som ogsaa beklæder Udførselsgangen,
Fig. 3, g, 4, /. Flere af Kjertierne indeholdt en Samling
af klare Molekiiler (Slim). Til Matrix støder et meget tyndt
Bindevævslag, Fig. 3, h, 4, g, hvortil den sædvanlige
Muskelhud er bunden, Fig. 4, h.
Der er kun en Retractor, som tager sit Udspring lige
bagenfor Kroppens Midtpunkt med to temmelig lange
Rødder, Fig. 2, a, følger Bugfladen, Fig. 2, b, og fæster sig
fortil strax bagenfor Tentakelkrandsen.
Phascolosoma Lilljeborgii, n. sp.
PI. I., figs. 1—4.
Total length of the largest specimens 80""". The trunk,
fig. 1, a, measuring 40mm in length and 2mm in thickness, is
cylindrical, with the posterior extremity slightly acuminate;
it has a smooth, nacrous, almost hyaline skin, sparingly
furnished with papillæ, so minute as to be with difficulty
perceptible under a strong magnifier; on the base of the
proboscis, and on the posterior portion of the trunk, the
disposition of these papillæ is somewhat closer.
The proboscis, fig. 1, b., which can hardly admit of
being wholly retracted within the trunk, is 40mm long, smooth,
nacrous, studded with exceedingly minute papillæ, and bears
at its extremity a cincture of short and rather broad
ten-tacula, fig. 1, c, encircling the round buccal aperture.
Anal opening circular, åt the base of the proboscis,
«g i, d.
The skin is composed of an extremely thick, finely
striated chitinous layer (the cuticlé), figs. 3, a; 4, a,
underneath which lies the epithelium (the matrix), figs. 3, b; 4, b,
consisting of a layer of rather large cylindrical cells.
In the epithelial layer — more especially on the
proboscis — occur numerous glands, jbroad at the base, figs. 3, c;
4, c, and with .a tapering excretory canal, figs. 3, d; 4, d,
which pierces the thick chitinous cuticle, on the surface of
which it opens into a funnel-shaped cavity, figs. 3, e; 4, e.
Each gland consists of a somewhat thin capsule of
connective tissue, fig. 3, /, covered on its inner surface by the
epithelium, which also invests the excretory duct, figs. 3, g;
4, /. Several of the glands contained an aggregation of
pellucid molecules (mucus). Contiguous to the matrix
extends ja very thin layer of connective tissue, figs. 3, h;
4, g, to which is webbed the ordinary muscular
integument, fig. 4, h.
There is only one retractor, which takes its origin
immediately posterior to the medial point of the trunk, with
two longish roots, fig. 2, a, protends along the ventral
surface, fig. 2, b, and is attached to the proboscis in close
proximity to the cincture of tentacles.
1*
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