14 
D. C. Danieissen. 
[No. i. 
mediately over into a well developed intestine that terminates in 
an anus (Pl, II fig. 7). 
The gullet-tube (oesophagus) is cylindrical, 8 m. m. in length, 
and 4 m. m. in breadth just at the oral aperture (Pl. II fig. 7 a), 
diminishing somewhat in thickness as it passes over into the in- 
testine (Pl. II fig. 7 b). The intestine becomes a little dilated im- 
mediately below the oesophagus, and passes in almost a straight 
line towards the posterior extremity, where it again dilates itself 
a little, in order to, as a rectum (Pl. II fig. 7 c), terminate in the 
round anus. On the exterior side of the gullet-tube and intestine, 
the insertions of 12 septa are observed (Pl. II fig. 7 d); at a distance 
of a couple of millimetres from the anus, there is seen — on the in- 
testine (rectum), exactly in each longitudinal belt, consequently be- 
tween each two septal insertions — an extremely fine fissure about 
2 m. m. in length (Pl. II fig. 7 e), and, as we shall subsequently 
see, it leads right into the rectum. The inner surface of the gullet- 
tube is longitudinally folded, and the folds are relatively very 
broad (Pl. II fig. 6 a); as the gullet-tube passes over into the in- 
testine the folds become narrower, but a little way back in the 
intestine they project more forward, and assume almost the foliace- 
ous form (Pl. II fig. 6 b) whilst in the posterior part (rectum) they, 
become extremely narrow, become placed closer together, and are 
present in far greater abundance (Pl. II fig. 6 c). 
The covering of the body is formed of a mucous mass on 
whose exterior surface scattered grannules of sand are seen to be 
entrenched, whilst the interior surface is smooth* and has no organic 
connection with the integument of the body. The latter has a 
pretty thick ectoderm, consisting of a layer of long, narrow, ciliat- 
ing cylinder-cells with nucleus and nucleus-corpuscle (Pl. II fig. 8 a). 
Between the cells, and partly covered by them, claviform unicellular 
mucous glands are observed (Pl. II fig. 8 b), also a multitude of 
nematocysts (Pl. II fig. 8 c). These last are especially richly pre- 
sent on the tentacles and oral disc. Inside of the ectoderm, there 
is a fibrillous connective-tissue layer (Pl. II fig. 8 d) rich in connec- 
tive-tissue bodies with prolongations, and also nutritory ducts. 
Towards the inner surface of this connective-tissue there is found 
a rather narrow belt of circular muscles that appear to be situated 
in bundles but are not much developed (Pl. II fig. 8 e). On the 
inner surface of the connective-tissue, longitudinal and transversal 
muscles are secured (Pl. II fig. 8 f) and are covered with cylinder 
epithelium (Pl. II fig. 8 g). ' 
