295 
been piovided with a free stalk. Another species Zygophylax 
grandis ^ anh., which must be referred to the same genus, bas later 
been desciibed by \ anhoffen. 1 ) Though Abietinaria lacks both 
peripheral tubes and nematothecae the agreement between the 
species of this group and those of Abietinella in the form of the 
hydrothecae and the structure of the operculum is so great, that I 
cannot doubt but that the former genus must be derived from the 
, latter. The presence and the development of the nematothecae in 
the neaily lelated species, referred to Zygophylax , Pensiphonia and 
Lictorella, is subject to very great variation, and the same holds 
good for the composition of the colony, not only in the same form- 
group, where the peripheral tubes have a very different extension, 
but also in a number of genera belonging to the Campanulinidae 
and Sertulariidae. I have already spoken of the differences in the 
form of the colony within the genus Stegopoma, and I shall still 
only mention that while the stem in the Sertulariidae is monosi- 
phonic, as a rule, a small number of Sertularella-s^OAvs possess a 
polysiphonic stem. The gonothecae have not yet been found in any 
of the two Abietinella- species, but it is permissible to suppose that 
they are arranged in the form of a Coppinia, as this arrangement 
has been found in the related species Perisiphonia conferta , Zygo¬ 
phylax ( Brucella) armata and in a new species of Zygophylax 
from the Philippine Islands. As the presence of a Coppinia in a 
freely growing colony seems to be contingent upon the presence of 
peripheral tubes, the disappearance of the latter might explain 
the quite different arrangement of the gonothecae in Abietinaria , 
where they as in the great plurality of the Sertulariidae are placed 
in the neighbourhood of the single hydrothecae. 
The short-stalked Thyroscyphus -species Th. ( Parascyphus) 
simplex Lmx. 2 ) Th. Torresi Busk (= Th. simplex Allm. 3 ) and 
Th. vitiensis Markt. 4 ) stand in a similar relation to Sertularella as 
9 50. 
2 ) 53, p. 158. 
3 ) 5. 
4 ) 36, p. 210 and 9, p. 343. 
