292 
belt representing the upper part of tke side-walls after tlie roof 
has been thrown off, and the only difference between the operculum 
in the three former genera and that of the two latter is that in 
Campcinulina and Opercularella it has been cleft in a numbei of 
segments, which, however, together represent the whole belt. Tliese 
segments are really not triangular, but about rectangular or tongue- 
shaped, and only seem to be triangular because they cover each 
others’ margins. Besides, the proboscis of Campanulina and Oper¬ 
cularella is according to Hincks conical and not claviform as in 
the Campanulariidae, and on the whole there eau be no doubt but 
that the two genera must be derived from the Lafoeidae. 
The species of the genus Thyroscyphus 1 ) rernind us, botli 
in thé form of their short-stalked hydrothecae and in the stiucture 
of the colony, of such inoperculate species as „ Obelia u marginata 
Allm., 1 ) „ Campanularia u insignis Allm./ 2 ) „Campanularia" juncea 
Allm. 3 ) and „ Campanularia “ rufa Bale, 4 ) all of which possess moie 
or less elongate, somewhat bilaterally symmetrical hydrothecae. The 
form of the proboscis is not known in any of these species, but in 
Th. simplex I have found a conical proboscis, and the same form 
of proboscis has also been found by Ritchie in Thyroscyphus 
simplex Lmx. (non = Th. simplex Allm.), for which he has 
instituted the genus Parascyphus. The latter species is distinetly 
bilaterally symmetrical and provided with a blind sack, and Ritchie, 
therefore, refers it to the Sertulariidae, but as the hydrothecae 
have a short stalk I prefer to refer it to the Campanulinidae. It 
is, however, doubtful whetlier this species is sufficiently different 
from the species of Thyroscyphus to represent a proper genus. 
The tripartite operculum is not a sufficient, distinguishing charactei, 
and also the other species of Thyroscyphus present a more or less 
developed bilateral symmetry. Perhaps they also possess a blind sack. 
A comparison between the different opercula found in the 
V ) 3. 
2 ) 5. 
3 ) 2 . 
4 ) 7 . 
