265 
The Thujaria-group is characterized as follows: ,,Die Hydro- 
theken mehr oder weniger alternirend, oft fast opponiert gestellt, 
dicht benachbart und mehrere bis viele auf ein Internodium ge- 
| 1 ke Sas: ; Mindung der Theca meist glatt, Deckel einfach. — 
Hierher gehåren: Diphasia alata Hincks, Sertularia filicula E1l. 
et Sol., abietina L., argentea Ell. et Sol., cupressina L., Thujaria 
thuja u. lonchitis; Sertularia diffusa Allmann, elongata Lmx., 
tenera Sars, maplestonei Bale, huttoni, Diphasia mutulata Busk, 
Dynamena tubuliformis Markt.” Of the above species Diphasia 
alata and D. mutulata, Sertularia filicula and S. abietina belong 
to Diphasia (the two latter to the subgenus Abietinaria), Sertularia 
argentea, S. cupressina, S. tenera and Dynamena tubuliformis to 
Sertularia, Thujaria thuja and Th. lonchitis to Thujaria and Ser- 
tularia maplestonei to Odontotheca. An opercular apparatus has 
hitherto not been found in Sert. elongata and S. huttoni, both of 
which have the hydrothecal margin provided with 6—7 teeth, and 
if they possess an operculum I am most inclined to think that 
it consists of as many valves as there are teeth. In either case 
these two species cannot be referred to any of the hitherto de- 
scribed genera. -— 
Schneider!) after having given the above phylogenetic 
sketch declares, that to penetrate deeper into the phylogeny of the 
Sertulariidae the close examination of a large living material shall 
be necessary, especially in order to make a thorough study of the 
difficult opercular apparatus. I quite agree with the author on 
this point, but as long as he adheres to the view that the colonial 
characters are the true generic characters, I cannot see that the 
results of such a study may be of any great use to him. He 
concludes his phylogenetic considerations with the following wish: 
»So steht denn zu hoffen, dass die zuktnftige Forschung wohl im 
Einzelnen das hier vertretene System nåher ausbauen und er- 
låuteren, nicht aber es zu Gunsten eines einzelnen diagnostischen 
1 p SE 
