198 
the mouth (PI. Ill, fig. 7). The mesogloea (6 — 20 p.) is a homogeneous layer. The ento 
derm (max. 33 ix) has the same structure as in the tentacles. 
The oral cone, which is high and cylindrical (PI. V, fig. 8) has nematocyst-batteries in 
its ectoderm-, these batteries are not surrounded by glandcells. Its entoderm contains a layer 
of circular musclefibres. The oral cone is constricted at its base, below the free border of the 
actinopharynx but above the base of the sagittal tentacles. In PI. V, fig. 9 the section through 
the bodywall attains the higher, bulging part of the oral cone. 
The Axis-layers have disappeared, except the connecting septum, which is short. 
The actinopharynx (PI. Ill, figs. 6, 7 and 9; PI. V, fig. 8) has a folded ectoderm 
(40 u); the folds do not correspond with the places of attachment of the mesenteries. The folds 
increase in number in the lower part of the actinopharynx. The ectoderm contains a superficial 
layer of actinopharyngeal glandcells. A layer of musclefibres is usually absent but in some 
places the ectodermal limit of the mesogloea stains very deeply, which is very like a thin layer 
of musclefibres (PI. Ill, fig. 7). Their direction is not to be distinguished, but probably they 
are longitudinal ones, since musclefibres are more easily to be distinguished in cross-sections 
than in longitudinal sections. The ectoderm contains darkbrown pigment, which increases in 
quantity in the lower parts of the actinopharynx. The mesogloea (5 —14 p.) is a homogeneous 
layer, increasing in thickness at the places of attachment of the mesen¬ 
teries. The entoderm (25 p.) contains no deeply staining glandcells 
and no pigment. There is a distinct layer of slightly developed 
circular musclefibres (PI. Ill, fig. 9), which are more crowded than 
the circular fibres in the entoderm of the oral cone. — The actino¬ 
pharyngeal lumen, which is a slit in its upper part, is more rounded 
in its lower part, and the actinopharyngeal wall is curved towards 
the wall of the oral cone. The actinopharynx descends no deeper 
than halfway the oral cone (PI. V, fig. 8), except along the sagittal 
mesenteries where it descends to a much lower level, so that the 
actinopharyngeal wall is a semi-circle in a vertical cross-section of 
the polyp. 
Mesenteries (PI. Ill, figs. 4, 6, 7 and 8; PI. V, figs. 8 and 9). — 
They are normal in number. Their musclesystem is apparently very 
divergent. The mesenteries have unilateral mesogloeal lamellae, which 
bear well developed musclefibres, often arranged along small secon¬ 
dary lamellae. The system of longitudinal musclefibres is figured in 
the textfigure 259. On one pair of sagittal mesenteries these fibres 
are found on the sides facing each other, while on the other 
pair of sagittal ones these fibres are probably found on the averted 
sides, at least on one of these mesenteries with certainty. The lamellae on the other mesenteries 
are arranged in an entirely different system in both halves of the polyp. In one half they are 
on those sides of the secondary mesenteries, which are averted from the transversal primary 
ones (PI. Ill, fig. 7), while in the other half they are turned towards the primary transversal 
S P) 
Fig 259. Eucirripathes 7 >iuscnlosa 
v. Pesch. System of the longitudinal 
musclefibres on the mesenteries (for 
the text cf. the list of abbreviations 
before the plates). 
