277 
Sertularella I cannot refer them to this genus. We might with 
the same light refer f. inst. the inoperculate species “ Obelia ’ 
marginata Allm.*), Campanularia insignis Allm. 2 ) and Camp. jun- 
cea Allm. 3 ) to Thyroscyphus, because they agree with the species 
of this genus in the form and the arrangement of the hydrothecae. 
From the National Museum of Washington I have received a 
small fragment of the original specimen of Sertularella magna 
Nutt. It contains 12 hydrothecae, the 6 of which have the margin 
more or less injuried, while in the 6 others it is intact, and 
provided with three distinet curves, divided from each other by 
as many distinet teeth (pi. IV, figs. 27, 28). When regarded 
from above the aperture is distinetly triangular with curved sides. 
In none of them have I found a complete operculum, but in some 
of them small remnants of the opercular valves still adhere to 
the curves, and in a single hydrotheca two complete valves are 
fixed each in its curve while the third is missing. The species 
seems to be very fragile, but there can be no doubt that the 
hydrothecae when undamaged are provided with three opercular 
valves, and that Nutting’s divergent statement must be explained 
as an incorrect interpretation of acccidental injuries. The hvdro- 
thecae have been regenerated 4—6 times. 
Dictyocladium (Allm.) Nutting. 
The latter part of Prof. Nutting’s diagnosis of Sertularella 
does not mean that an operculum of three or four valves cannot 
be found in species which possess a flabellate colony with ana- 
stomosing bianches, but only that such species are referred by the 
author to the artificial genus Dictyocladium. While D. dichotomum 
Allm. does not seem to possess an operculum the two other species 
referred to this genus, D. flabellum Nutt. and D. reticulatum Krp. 
belong to Sertularella. Of the latter species I have examined a 
fragment sent to me from the Zoological Museum of Hamburg, and 
*) 1, pi. VI, figs. 1, 2. 
2 ) 5, pi. IX. 
3 ) 2, pi. 11 , fi g8 . 3 , 4. 
