korresponderer med Kropshulheden; thi aabenbart kan 
Spalten udvide og sammentrække sine Leber, alt eftersom 
Stromningen skal gaa ind eller ud, — en Organisation, der 
er ganske fremmed for Gephyreerne. 
‘Mundaabuingen er omgivet af en muskuløs Vold. 
Spiserøret er omtrent 2.5”” langt, Fig. 11, b, og har paa 
sin indre Flade stærke Længdefolder, som rage temmelig 
langt ind i Hulbeden., Hvor Spiserøret gaar over i Tar- 
' men er en Indsnøring, Fig. 11, c, som danner ligesom en 
Ring paa den mdre Flade. 
Tarmen, Fig. 10, 11, er meget vid og indtager en 
stor Del af Kropshulheden; den har en lige Retning bag 
mod Kroppens bagerste Ende, hvor den danner en yderst 
kort Rectum med en rund Analaabning. Den er i hele 
sin Længde paa Bugfladen og Siderne til henimod et Par 
Millimeter fra Analaabningen forsynet med en Mengde 
brede ringformige Folder, Fig. 10, a; 11, d, der rage langt 
ind i Tarmens Lumen. 
Tarmens Rygflade derimod er glat og har paa den 
udvendige Side et stærkt muskuløst Baand, Fig. 11, e, der 
ved en Mængde Bindevæys- og Muskeltraade er nøie bundet 
til Kropshulhedens Rygflade, saa at der intet Mellemrum 
findes imellem denne og Tarmen. Det indre Hpithel, der 
beklæder Tarmen og dens Folder, dannes af temmelig store 
Cylinderceller, der — foruden Kjerne og Kjernelegeme — 
indeholder et kornet Protoplasma, Fig. 14, g; mange af 
disse Celler ere meget store og have en temmelig bred 
Grunddel, og kunne muligens tjene som Afsondringsorganer ; 
forøvrigt er Tarmens histologiske Bygning som hos Gephy- 
reerne i Almindelighed. 
Spiserøret var temmelig fast bundet til Kropsvæggen 
ved mange muskuløse Baand, hvoraf enkelte vare meget 
lange. Tarmens Bugflade var ved et stærkt Mesenterium 
fæstet til Kropsvæggen, 
Der var ingen af de buskede Organer ved Rectum, 
som findes hos Bonellia, Thalassema, Echiurus og Hamingia. 
Hvad vi kunne meddele om Nervesystemet er desto- 
værre meget ufuldkomment Å thi Dyrenes slette Konserva- 
tion har gjort det umuligt at kunne forfølge det i sin Hel- 
hed; ved Hjælp af endel Tversnit have vi dog kunnet ud- 
rede noget. 
Nervestrængen følger langs Bugfladen ved Siden af 
Tarmmesenteriet og imellem Tarmyeggen og Kropsvæggens 
indre Ringmuskellag, fra Anus til den forreste Del af 
Spiserøret. Den er ikke indesluttet i noget Kar; men i 
dens Centrum er et Lumen, Fig. 14, h, hvori vistnok cir- 
culerer en Vædske og kan betragtes som et Centralkar. 
Et saadant har ogsaa Greeff iagttaget hos: Echiurus Pa- 
lassit, 5 
* Ueber den Bau-und die Entwickelung der Echiwrus von R. Greeff. 
Aus den Sitzungsberichten der Gesellschaft zur Beförderung der ge- 
sammten Naturwissenschaften zur Marburg, No. 2, Februar 1874. 
Den norske Nordhavsexpedition. Danielssen og Koren: Gephyrea. 
41 
kind of respiratory apparatus, through which the sea-water 
is made to communicate with the perivisceral cavity; for 
the labia of the fissure can evidently expand and contract, 
for the admission and expulsion of the circulating fluid, 
— a peculiarity of organisation altogether alien to the 
Gephyrea. 
The buccal aperture is surrounded by a muscular 
ridge. The gullet, about 2.57” long, fig. 11, b, exhibits 
on its inner surface prominent longitudinal folds, extending 
comparatively far down into the cavity. Where the æsopha- 
gus passes into the intestine, is seen an instriction, fig. 11, 
c, forming, as it were, a-ring on the inner surface. 
The intestine, figs. 10; 11, 1s exceedingly wide, occu- 
pying a considerable portion of the perivisceral cavity; it: 
protends almost straight back towards the posterior extrem- 
ity of the body, where it opens into an exceedingly short 
rectum, with a round anal opening. It is furnished through- 
out its entire length on the ventral surface, and on the 
sides, to within a millimetre. or two from the anal opening, 
with numerous broad annulary folds, figs. 10, a; 11, d, 
projecting far down into the lumen of the intestine. 
The dorsal surface of the intestine, on the other hand, 
is smooth, and furnished on the outer surface with an ex- 
ceedingly muscular band, fig. 11, e, closely webbed by 
numbers of membranous and muscular filaments to the dor- 
sal surface of the perivisceral cavity, no space being left 
between the latter and the intestine. The inner epithelium, 
investing the intestine and its folds, is composed of com- 
paratively large cylindrical cells, which, exclusive of a nu- 
cleus and a nucleolus, contain granulous -protoplasma, 
fig. 14, g; many of these cells are exceedingly large, with 
a broadish base; they perform, possibly, the ,office of secre- 
tory organs; for the rest, the histological structure of the 
intestine is that usually distinguishing the Gephyrea. 
The æsophagus was strongly webbed to the wall 
of the body by numerous muscular bands, some of them 
remarkably long. The ventral surface of the intestine was 
attached to the wall of the body by a strong mesentery. 
No trace of the bunchy organs observed on either side of 
the rectum in Bonellia, Thalassema, Echiurus, and Hamingia. 
Unfortunately, we have but little to record of the 
nervous system; for owing to the bad state of the specimens 
it could not possibly be traced throughout; a few transverse 
sections enabled us however to observe some of its cha- 
racteristics. 
The nervous chord runs along the ventral surface. 
accompanying the intestinal mesentery between the wall of 
the intestine and the inner annular muscular layer in the 
wall of the body, from the anus to the anterior part of 
the cesophagus. It is not enclosed in any vessel; but in its 
‘centre there is a lumen, fig. 14, h, no doubt containing a 
circulating fluid, and this may be regarded as a central 
vessel. Greef observed a similar vessel in Hehiwrus Palassi. 
1 Ueber den Bau und die Entwickelung der Echiurus von R. Greef. 
Aus den Sitzungsberichten der Gesellschaft zur Beforderunge der ge- 
sammten Naturwissenschaften zu Marburg, No. 2, Februar 1874. 
? 6, 
