199 
mesenteries (fig. 259 to the left). On these transversal mesenteries the longitudinal musclefibres 
are found on the anterior side in one half of the polyp and on the posterior side in the other 
half. — This musclesystem on the primary transversal mesenteries is the same as in one of 
the young polyps of Eucirripathes contorta , but this young polyp has the same system on its 
secondary mesenteries in both polypar halves. — In an other series of sections I find in both 
halves of the polyp the same system of musclefibres; both halves have the system which is figured 
in the right half of fig. 259, but the fibres on the sagittal mesenteries could not be observed. — 
It is not unlikely that the system of fig. 259 is a combination of the longitudinal system and 
the transversal musclefibres, since the direction of both systems is very much influenced by the 
curving of the oral cone and the actinopharynx, as is described and figured in fig. 254. The 
fact that the horizontal sections are somewhat oblique makes it possible that the fibres which I 
observed were not all of them longitudinal ones. The right half of fig. 259 gives the situation in 
a somewhat higher part of the oral cone than the left half; so the right half represents without 
doubt the longitudinal fibres, but the left half may give the transversal fibres. One of the excep¬ 
tions, which remain, are the fibres on the left sagittal mesentery (Sp„), which ought to have the 
fibres, if they were transversal ones, on the averted side. But the sagittal mesenteries are so 
very near each other and the obliqueness of the section is of so little importance on this side 
that we may consider the fibres on both sagittal mesenteries as longitudinal ones. — The only 
exception, which remains, is the position of the longitudinal fibres on one of the other pair of 
sagittal mesenteries, but since the section is in this part more oblique through a contortion of 
the polyp it is always possible that we have transversal musclefibres here. However this point 
is not to be decided with certainty since the other sagittal mesentery of this pair does not 
show any trace of musclefibres. — I am of opinion that after all the mesenterial musclesystem 
of this species is the same as in Eucirripathes anguina a. o. — The mistaking of transversal 
musclefibres for longitudinal ones is the more possible in this species since the transversal fibres 
are highly developed, although it is true that they are not so strong as the longitudinal fibres; 
their mesogloeal lamellae are rather low (PI. Ill, fig. 8). In vertical sections the mesenteries, 
which follow the downward and outward curve of the actinopharynx, are attained lengthwise 
in the upper part of the oral cone, but obliquely or even cross-wise in the lower part of the oral 
cone. In PI. V, fig. 8 the oral cone is figured in vertical cross-section but the actinopharyngeal 
wall is curved so much that it is attained obliquely. The primary transversal mesentery out of 
this figure is figured in PI. Ill, fig. 8 also; at the side of the top of the oral cone this mesentery 
is attained lengthwise so that the transversal musclefibres are visible in cross-section (tr. sp.), 
while at the side of the actinopharynx the longitudinal fibres are attained in cross-section and 
so they are visible in their turn. The longitudinal section of both layers of fibres is never 
clearly visible; at the utmost the dark limits of the mesogloea are a sign of their presence. — 
In this fig. 8 on PI. Ill the mesogloeal lamellae for the longitudinal musclefibres are the 
longest. — These transversal fibres were found also on the other mesenteries, but not so highly 
developed. — Generally the entire musclesystem is strongest on the transversal mesenteries; 
they are somewhat less developed on the secondary mesenteries, while they are very slightly 
developed on the sagittal mesenteries (PI. Ill, figs. 6 and 7). 
