2 30 
and they are separated from the mesentery by a deep constriction. They are straight along 
the primary sagittal mesenteries but convoluted and branched along the primary transversal 
ones. There is no pigment. 
Reproductive organs. The primary transversal mesenteries contain a small number of 
testes with a very thin mesogloeal capsule. They are found in that part of the mesentery, 
which also bears the filaments, and they take up a small part only, near the place, where the 
mesentery is fixed to the bodywall. The testes are unilaterally distributed on that side of the 
mesentery, which may bear the transversal musclefibres also. All the testes are in the same 
stadium of ripeness, filled with a bundle of spermatozoa. The capsule is oval with a long axis 
of max. 90 1 .>.. Their mode of origin is the same as in the preceding species. — In one of 
the series of sections a number of ripe testes-vesiculae are lying free in the actinopharyngeal 
lumen, very near the mouth. They are still surrounded by a thin mesogloeal layer. We cannot 
decide whether this a normal method of liberating Pie spermatozoa or whether they are accidentally 
shifted hither by preservation etc. The latter is probably the case. 
Parasites. There is a large parasite, which fills almost the entire gastral cavity. It is 
a Plathelminth; the series of sections through the attained polyp is rather bad, since the 
sections of the parasite do not always remain fixed in the gastral cavity. The following data 
could be made out: the parasite is long and flat without segmentation. One of the planes is 
bent, so that the sides of the body are V-shaped. It is covered with a unicellular epithelium with 
a striped cuticula; there is a subepithelial layer of longitudinal musclefibres; parenchymatose 
cavities are separated by dorso-ventral musclefibres. Testes and ovaria are arranged bilaterally. 
The digestive canal is without an anus; it begins with a very muscular proboscis, projecting 
on the middle of the ventral side. Near this proboscis there is a brain with a great number 
of ganglion cells. There are six longitudinal nerves, two pairs on one side of the body and 
one pair on the opposite side. There are two strong nerves besides, which go laterally from 
the brain towards the sensory organs. There are paired openings for the two penes, which 
are to be seen through a great part of the body as horny, slightly curved tubes with basal 
muscle-system. One single parasite is found in several neighbouring polyps, for its body is 
indented by an interzooidal septum. 
28. Stichopathes semiglabra ' sp. n. (PI. VI, fig. 4). 
The ectoderm and the entoderm have disappeared and the mesogloea only remains, 
together with the actinopharyngeal ectoderm. — This ectoderm (58 p.) is rich in 
actinopharyngeal glandcells, with a few of a larger type. There is no pigment; the longitudinal 
musclefibres are slightly developed. The mesogloea bears lamellae, which project far into the 
actinopharyngeal lumen (PI. VI, fig. 4); in the upper part of the actinopharynx these lamellae 
(14 p. long) are to be found at the sagittal ends, but at a lower level they become more 
numerous and they project farther (28 p.) into the lumen. 
There are ripe testes in the gastral cavity, near the primary transversal mesenteries, 
but probably freed by the maceration of the tissues. 
