235 
group and, in opposition to Stephenson’s classification, to my mind 
not belonging to the Metridiidae. There are, indeed, in the anatomy 
of Åiptasia and allied genera some points which certainly need a 
revision. Concerning the sphincter, we see in Stephenson’s diag- 
nosis, based mostly on statements by previous authors, that Åip¬ 
tasia and Heteractis have a mesogloeal sphincter, Åiptasiomorpha, 
among other species Å. diaphana, and Bartholomea no sphincter. 
The sphincter of Carlgreniella is, according toWatzl, mesogloeal. As 
to the type species of Åiptasia, Å. couchii, Stephenson has shown, 
that it is provided with a mesogloeal sphincter, completely imbed- 
ded in the mesogloea. Through kind obligingness of Stephenson 
I have had the opportunity to control the correctness of his state¬ 
ments on some of his sections. FTirther I have recieved from him^) 
a glass with 3 specimens of this species and sectioned one of them, 
and also here the mesogloeal sphincter was distinet. On the other 
hånd, an examination of two specimens from the station in Ply- 
mouth, which were smaller than the others ( 2,4 resp. 2 cm long 
and 1,2 resp. l,i cm broad at the oral disc) showed no distinet 
mesogloeal sphincter. In some sections I have not observed any 
sphincter, in other sections there were, however, rudiments of 
muscle-fibrils in the mesogloea. Thus it seems that the mesogloeal 
muscle meshes here arise rather late. Besides, the sphincter in Å. 
couchii is weaker than in the other species mentioned below, and 
the muscles separated from the endoderm only by a very thin 
mesogloeal lamella. Concerning the sphincter in Heteractis lucida, I 
can confirm the statement of MciVlurrich and Watzl that it is 
mesogloeal. On the other hånd, Duerden declares that there is 
no sphincter in this species (1899 p. 356). I have sectioned one 
part of a specimen recieved from Duerden and certainly invest- 
igated by him, and there was indeed a mesogloeal sphincter pre¬ 
sent. The sphincter of Carlgreniella is likewise mesogloeal. Bar¬ 
tholomea has no sphincter in Stephenson’s diagnosis. Watzl 
has however stated that B. annulata and werneri are provided with 
a mesogloeal sphincter. I have controlled Watzl’s statement and 
come to an identical result (2 specimens of B. annulata and one 
9 I beg here to express my best thanks to Dr. Stephenson for sending 
me this material. 
