24 1 
The musclesystem is clearly visible in several species; usually there are unilateral longi¬ 
tudinal musclefibres, supported by mesogloeal lamellae, sometimes with secondary lamellae. The 
system of transversal musclefibres is not so well developed and its mesogloeal lamellae are much 
shorter. In fig. 262 I have put together the different systems of mesenterial musclefibres, as they 
were found in the examined species. — Ed. van Beneden calls that part of the polyp, where the 
sixth pair of secondary mesenteries appears, the anterior part. So this anterior part is without 
further difficulty indicated in Eucirr. contorta (!)■ the longitudinal musclefibres are then placed 
on the posterior side of the primary transversal mesenteries. Suppose all the Antipatharia, 
which have these musclefibres, possess the longitudinal musclefibres on the same side of these 
mesenteries, II to A" of fig. 262 give the musclesystems of the other species in such a manner 
Fig. 262. Schemata of the systems of longitudinal 
I Eucirripathes contorta v. Pesch. 
II Eucirripathes anguina v. Pesch. 
III Eucirripathes musculosa v. Pesch. 
IV Stichopathes variabilis n. n. 
V Stichopathes solorensis sp. n. 
musclefibres on the mesenteries of various species 
VI Stichopathes gracilis (Gray) em. 
VII Stichopathes saccula sp. n. 
VIII Stichopathes ceylonensis T. & S. 
IX Euantipctthes plana (F. C.). 
X Euantipathes longibrachiata n. n. 
that they may be compared with Eucirr. contorta. It appears that these systems may be arranged 
into groups. One of these groups is represented best by Stick, ceylonensis (VIII). To this group 
also appertain Eucirrip. contorta (/), Eucirr. anguina (II), Stick, variabilis (IV), Stick, solo¬ 
rensis (V) and Euant. plana (IX). That is to say that the mesenterial musclefibres of these 
species are also present in Stick, ceylonensis , but not that all of them have a complete system. 
Euant. plana (IX) is the less developed, for there are only mesogloeal lamellae on the primary 
transversal mesenteries and the anterior secondary mesenteries, but without musclefibres! In IV 
and V the primary transversal mesenteries and both pairs of secondary ones bear musclefibres, 
but not the sagittal mesenteries. / has musclefibres besides on the anterior sagittal mesenteries, 
while II as well as VIII have a complete musclesystem on all the mesenteries, which system 
is not everywhere visible with absolute certainty in II. This system is: the longitudinal 
musclefibres are found on the anterior side of the anterior sagittal pair 
and of the anterior secondary pair, but on the posterior side of the other 
three pairs of mesenteries. 
SIBOGA-EXPEDITIE XVIf. 
31 
