The Norw. North- Atlantic Exped. 
i 7 
connective-tissue beams are clad with pretty long cylinder-cells 
carrying ciliæ (Pl. III fig. i h), and between which unicellular mu- 
cous glands are, here and there, observed; especially does the 
posterior part of the intestine appear to be rich in such glands. 
A transversal section of the posterior part of the rectum; just 
at the point where the fine fissures previously mentioned are found, 
upon the exterior surface; shows that those fissures lead direct 
in to the intestine. In this situation the intestine is much dilated, 
and from its inner surface 12 canals bulge out; thcse are oblong, 
penetrate through the connective-tissue — which is, here, not very 
broad — and open out exactly in the interval between 2 septa, 
where the fissures named are found (Pl. II fig. 11 c). These canals 
are clad with epithelium, consisting of ciliating cylinder-cells (Pl. 
II fig. 1 1 d), like that which clothes the inner wall of the intestine, 
and in it there are seen, here and there, a few oblong, quite clear 
and empty cells, which are, presumably, mucous glands (Pl. II fig. 
il e). Here there appears to be almost a kind of cloacum into 
which the fissures open. In the transversal section illustrated, 4 
such canals are seen, but there are really 12, which may be seen 
on comparison of several closely continuous sections, by which the 
true number is brought out. Here, therefore, a direct communi- 
cation between the chambers and the intestine is found; which is 
not the case in F en ja mirabiUs, where the, presumably, genital fis- 
sures found in the bottom of the chambers, open around and out- 
side the rectum between the integumental papillæ or folds de- 
scribed, and thus communicate direct with the external medium (the 
sea-water). But both these descriptions of fissures certainly perform 
the same function viz, to lead the offspring out of the body. 
All the 12 septa carry mesenterial filaments and reproductive 
organs (Pl. II fig. 7). They first issue from the anterior part of 
the gullet-tube, exactly under the oral aperture, and are secured 
to the connective tissue membrane that forms the septum, and 
retreat, sinuously, backwards to about the middle of the in- 
testine. 
The ovaries are situated outside the mesenterial filaments, 
farther from the gullet tube and the intestine, but in front issue at 
the gullet-tube under the oral disc, and extend backwards almost 
right up to the genital fissures. In a few septa, however, they were 
not so long, but extended only a little way behind the anterior 
half-part of the intestine; but it may be, that these short ovaries 
are not fully developed. 
2 
