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belt representing the upper part of the side-walls after the 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 
Campanulina and Opercularellå it has been cleft in a number of 
segments, which, however, together represent the whole belt. These 
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- 
eularella is according to Hincks conical and not claviform as in 
the Campanulariidae, and on the whole there can be no doubt but 
that the two genera must be derived from the Lafozidae. 
The species of the genus 7'hyroscyphus!) remind us, both 
in the form of their short-stalked hydrothecae and in the structure 
of the colony, of such inoperculate species as ,, Obeliaf” marginata 
Allm.,”) ,,Campanularia" insignis Allm.,”) ,,Campanularia" juncea 
Allm.?”y and ,,Campanularia" rufa Bale,t) all of which possess more 
ør 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 åa 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 whether this species is sufficiently different 
from the species of Thyroscyphus to represent a proper genus. 
The tripartite operculum is not a sufficient, distinguishing character, 
and also the other species of Thyroscyphus present a more or less 
developed bilateral symmetry. Perhaps they also posséss a blind sack. 
A comparison between the different opercula found in the 
