synkninger i Bindevævet ere ikke saa dybe, og staa heller 
ikke saa tæt i hinanden, og foruden de almindelige Cylin- 
derceller, som i Spiserøret, findes der i Hpithelet en stor 
Mængde pæreformige encellede. Kjertler, Fig. 11, f' (Lever- 
celler), der svare fuldkommen til Tarmkjertlerne hos Bo-, » 
nellien. Disse Kjertler ligge tildels'i Grupper, der kunne 
sees med en stærk Loupe igjennem Tarmvæggen, Fig. 6, 
leg Up Dy Oe 
Naar den 5te Tverslynge «har naaet hen til høire 
Side, bliver den meget smalere. Tarmrøret løber nu i flere 
Bøininger skraa fortil under de tidligere omtalte paatvers- 
gaaende Slynger, lige henimod den første Tverslynge. Paa 
denne Strækning gjør den en Mangfoldighed af smaa Cir- 
cumvolutioner, Fig. 6, p, p. Nu bøier den sig hen mod 
venstre Side, hvor den gjør en Boining for at lobe langs 
denne i en horizontal Retning mod Kropshulhedens bagerste 
Trediedel, Fig. 6, q, g, hvor den danner en Slynge, Fig. 
6, r, for i samme horizontale Retning at gaa fortil imod 
Midten af Kropshulheden, Fig. 6, s, her skraar den over 
mod høire Side under de øvrige Tarmslynger; den bøier 
- sig nu i en skraa Retning mod Midtlinien af Kropshulhe- 
den, Fig. 6, ¢, og gjør atter en Mængde Circumvolutioner, 
indtil den gaar over 1 en paaskraa løbende Rectum, Fig. 
6, w, der først udvider sig lidt, men bliver saa smalere, 
idet den munder ud 1 Kloaken. 
Fra den 5te Tverslynge og indtil Analaabningen, — 
der svarer til den Del hos Bonellia viridis, som Lacaze- 
Duthiers har kaldet Analdelen, — har Tarmrøret den samme 
Bygning, som tidligere er angivet for den Del, der strækker 
sig fra Spiserøret til 2den Tverslynge, og er følgelig uden 
noget Kjertelapparat. 
Langs Tarmrørets Bugflade, især paa den forreste 
Del, sees et Bindevævsbaand, hvortil Bugmesenteriet er 
fæstet, og hvori et Blodkar iagttages; paa den bagerste Del 
er dette Bindevævsbaand tyndere. Det synes paa enkelte 
Steder at stramme Tarmen saaledes, at dennes Bugflade 
bliver foldet; men det er kun paa et Par Slynger, at saa 
er Tilfældet. 
Bugmesenteriet bestaar af en stor Mengde smalere 
og bredere Bindevævstraade, hvori tildels findes Muskel- 
fibre, hvilke fæste Tarmrøret til Kropshulheden. Et lig- 
nende Mesenterium, men langt zartere, iagttages ogsaa 
langs Tarmens Rygflade, der fæster denne til Kropshulhe- 
dens Rygflade. 
Kloaken er bunden ved en Mængde stærke fibro- 
muskuløse Baand til Kropsvæggen, hvilke udbrede sig 
straaleformigt paa denne og danne derved ligesom et Telt, 
Fig. 6, v, under hvilket 2de buskede Organer ere placerede, 
et paa hver Side af Rectum. Tarmrørets ydre Flade er 
forsynet med et flimrende Peritonealovertræk. 
Den norske Nordhavsexpedition. Danielssen og Koren: Gephyrea. 
25 
‘ 
canal, the walls are thinner; the depressions of the epi- 
thelial layer (mucous membrane) in the connective tissue 
are not so deep, or so close together; and exclusive of. 
the ordinary cylindrical cells (those in the skin of the 
cesophagus, for instance), numbers of pyriform, unicellular 
glands, fig. 11, f (hepatic cells), occur dispersed throughout 
the epithelium — the exact analogue of the intestinal glands 
in Bonellia. Part of these glands are arranged in groups, 
‘which may be seen, under a strong magnifier, through the 
wall of the intestine, fig. 6, k, 1, m, 0. 
On reaching the right side, the Sth transverse cir- 
cumvolution diminishes very considerably in thickness. The 
‘intestinal canal now passes obliquely forward, twisting re- 
peatedly, beneath the transverse circumvolutions described 
above, to the first circumyolution. On its course it forms 
a great many small convolutions, fig. 6, p, p. It now bends 
across to the left side, along which it protends, after making 
a twist, in a horizontal direction, to the posterior third of 
the perivisceral cavity, fig. 6, q, q, where it forms a cir- 
cumvolution, fig. 6, 7, and then passes on, horizontally as 
before, to the middle of the perivisceral cavity, fig. 6, s; 
here it takes an oblique direction across to the right side, 
beneath the other circumvolutions, and then bends obliquely 
on towards the mesial line of the perivisceral cavity, fig. 6, 
t, again forming a number of convolutions, till it enters an 
obliquely protending rectum, fig. 6, uw, which expands a 
little at its commencement, but grows narrower where it 
disembogues into the cloacum. 
From the 5th transverse circumyolution to the anal 
opening, — which represents the part in Bonellia viridis 
termed by Lacaze-Duthiers the anal region, — the intestinal 
canal exhibits the structure described above as character- 
ising the part that extends from the æsophagus to the 2nd 
transverse circumyolution: hence it 
apparatus, 
has no glandular 
On the ventral surface of the intestinal canal — more 
particularly the anterior part — is seen a membranous 
band (webbed to the ventral mesentery), in which there 
is a blood-vessel: this membranous band has its posterior 
portion thinner than the remainder. In some places, it 
would appear to stretch the intestine, corrugating the ven- 
tral surface of the latter; this is the case, however, only 
with one or two of the convolutions. 
The ventral mesentery consists of numerous filaments 
of connective tissue, in some of which are muscular fibres, 
that serve to attach the intestinal canal to the peri- 
visceral cavity. A similar mesentery, but far more delicate 
in structure, is seen, too, on the dorsal surface of the in- 
testine, which it webs to the dorsal surface of the peri- 
visceral cavity. 
The cloacum is webbed to the wall of the body by 
numerous strong fibro-muscular bands, which, radiating on 
the latter, form, as it were, a tent-like enclosure, fig. 6, v, 
under which are placed two bunchy organs, one on either 
side of the rectum. The outer surface of the intestinal 
canal is invested with a ciliated peritoneal tunic. 
4 
