192 
glandular tract on the hyposulcus is not so distinet here as in I. 
bandanensis, and forms no offset from the hyposulcus. 
The textfigure 14 shows a diagram of the older mesenterie 
the largest uncoloured specimen. The second protomesentenes (p.) 
and the 4—5 older M- and m-mesentenes are provided with acont- 
oids The acontoids were of the same structure as in /. banda¬ 
nensis, the large nematoeysts in the endoderm part were, however 
not so numerous here as there, on the other hånd the giand ceUs 
were here more numerous. There is no distinet limit between the 
ciliated tract and the craspedion region judging from the sectione 
part of the left Ms-mesentery (the sectioned part was situated be¬ 
tween the two + marks in textfigure 14). The ciliated tract is 
namely interrupted, sometimes only the one ciliated strea P''®' 
sent as in /. bandanensis. The craspedion region is broad and shows 
no invagination in the middle line, its longitudinal muscles are 
strong. The large often curved nematoeysts in the endoderm of p 2 , 
M and m are not so numerous as in /. bandanensis. The - an 
m-mesenteries were fertile, but only few ova were present, 
have not observed any testes in the sectioned part. but cannot 
confirm their absence. / c 1 
The mesenteries of the uncoloured specimen (textfigure 15) 
with 27 marginal tentacles were somewhat otherwise structured than 
in the largest uncoloured specimen (textfigure 14). There were 
namely no distinet acontoids, only very small thickemngs in the 
most aboral part of the filaments in pe and the older M and m. 
The sections of these thickenings gave no definite results as o 
their structure but 1 think that they are no rudiments of acontoi s 
but probably of craspedion regions. The ciliated streaks namely 
reach to the thickenings. 
How are we to interpret this variation, in the one specimen 
acontoids (such were also present in the smallest specimen) in the 
other no such organs? As far I can understand, the abnormity o 
the specimen reproduced in fig. 15 can only be interpreted by the 
hypothesis, that the animal is a result of asexual repro uctiom 
Cerfontaine (Contribution å l’étude des Cérianthides. Arch. de 
Biol 1909 p 673) has namely proved that Arachnanihus (Ceriait 
thus) oligopodus is able to multiply by transverse fission (“scissi- 
parité spontanée”. Cerfontaine). After the fission the distal 
