There are slight circular musclefibres in the entoderm. The oral cone is not constricted at its 
base. In its mesogloea there are local crowdings of transversal fibres. 
The Axis-layers are lost for the greater part; as far as it can be made out, the layers 
were extremely thin. There are very frequent fusions between the bodywall and the sheath of 
the spines, which project also far into the gastral cavity. 
Actinopharynx. The lumen is slit-like in its upper part, with almost touching entoderm; 
in its lower part the lumen is a wide oval, almost a circle. The free actinopharyngeal border 
is curved upwards towards the bodywall. The ectoderm (55 y) is very much folded; there 
are many actinopharyngeal glandcells but no pigment. Longitudinal musclefibres are clearly 
visible. The homogeneous mesogloea is 1-—4 u. The entoderm (20 u.) has no muscle- 
fibres, and is of the same structure as in the bodywall. 
The mesenteries are normal in number. The entoderm is 15 y, the mesogloea 1 — ioy. 
The secondary mesenteries leave the bodywall at a higher level than on the actinopharyngeal 
side. Afterwards they are extended between the actinopharynx and its curved free border, and 
still lower down they are fused with the primary transversal mesenteries. — d hese secondary 
mesenteries are thicker on the actinopharyngeal side than on the side of the bodywall, and 
the same holds good for the primary mesenteries. The musclefibres are very distinct. I hey 
are rather slight on one of the pairs of primary sagittal mesenteries, somewhat better developed 
on the other sagittal pair, and very strong on the transversal mesenteries. 1 he musclefibres 
as well as the mesogloeal lamellae have the same aspect as in PI. Ill, fig. 7. In all the 
polyps (± 10) the following system is found. On the sagittal mesenteries the longitudinal muscle¬ 
fibres are situated on the averted sides of the mesenteries; on the secondary mesenteries they 
are all of them turned towards the primary transversal mesenteries, and on these they are 
found on the same, posterior, side. — This is the same system as in fig. 260. 
In the lower part of the mesenteries, where the bodywall and the actinopharynx are 
farther apart, the large mesogloeal lamellae of the primary transversal mesenteries are found 
on one tenth only of the entire breadth of the mesentery, on the actinopharyngeal side. In 
tangential sections of the oral cone the transversal musclefibres can be made out very distinctly. 
Their mesogloeal lamellae are almost as well developed as those of the longitudinal fibres. They 
are not found on the primary sagittal mesenteries, but on the transversal and the secondary 
ones they are situated at the opposite side of the longitudinal system. On that part ol the mesen¬ 
teries, which bears the mesenterial filaments the musclefibres on both sides ot the mesenteiy aie 
parallel with one another and with the free border of the mesentery. Both systems are so clearly 
visible that there can be no doubt about the exact mode of distribution of the musclefibres. 
The mesenterial filaments are single-lobed, of actinopharyngeal ectodermal structure, 
without pigment. They are round in section, as in PI. I, fig. 18. I hey are straight and 
unbranched along the sagittal mesenteries, but convoluted and highly branched along the 
transversal primary mesenteries. I hey project even into the base of the lateral tentacles. 
Reproductive organs are absent but still the gastral cavity is rather large, so that 
evidently the dimensions of the polyps are not entirely dependent upon the occurrence oi 
ovaria or testes. 
