316 
opercular apparatus, and the composition of the colony has referred 
the genus Idia-not only to an independent family, but also to a 
new section Thalamophora. AÅ correct description of the colony 
has been given by Bale”), and Billard”) has pointed out the 
presence of an adcauline operculum. 
Fig. UL 
| 
e 
Plate IV. 
Sertularia Nuttingi n. sp. Hydrothecae from the distal portion 
of the colony. Frontal surface. X 57. 
The same species, Distal partjon of the colony. Dorsal surface. 
47. 
x 
The same species. The distal end of a hydrotheca, seen from 
the frontal surface. X 66. 
A gonotheca of the same species. X 34. 
The distal end of a + hr btarten of Sert. Fabricii Lev., seen from 
its frontal surface. 
The distal end of 5 ig same hydrotheca, seen from the side. 
47. 
x 
Sertularia intermedia n. sp. Hydrothecae from the distal por- 
tion of a colony. X 34. 
"The same species. The distal end of a hydrotheca, seen from 
its frontal surface. Xx 66. 
The same species. The one side-half of the distal end of a hy- 
drotheca, extended. X 66. 
AÅ gonotheca of the same species. X 34. 
Sertularia decipiens n. sp. A portion ot a branch, seen from 
the side. X 20. 
The same species. A portion of a branch. Front view. X 20. 
Sertularia pumila L. A pair of hydrothecae showing distinct 
talks, and distally to each of them a translucent inner cavity- 
Trondhjem-fiord. X 34. 
The same species. Frontal view of the end of a hydrotheca 
x 66. 
The same species. Longitudinal section through a portion of a 
hydrotheca showing the stalk and the inner cavity between the 
latter and the hydrotheca. X 47. 
Sertularia Suensoni n. sp. Å portion of a branch. Front 
view. X 34. 
