MEDUSA. 37 
position of the gonads upon the radial canals is slightly variable. Some specimens 
have the gonads extending over the proximal half of the canals, and others over the 
central third portion of the canals. There is always a space between the stomach and 
the gonads, so that the species cannot be placed in the genus Isonema of Maas, which 
has the gonads adjacent to the stomach. 
One specimen still retains most of its tentacles, but the other specimens have, as 
usual, lost their tentacles, and only the stumps remain. The tentacles are long and 
thread-like, and have more the appearance of long cirri. They are too macerated for 
a detailed description of their structure. Sense organs were searched for, but not 
found. 
NARCOMEDUS. 
Famity AUGINID (Gegenbaur, 1856), Maas, 1904. 
SOLMUNDELLA (Haeckel, 1879), Maas, 1904. 
Generic Character.—Aiginide with two tentacles, and with a stomach having 
eight pouches. 
Prof. Vanhoffen (1908), in his revision of the Narcomeduse, recognises only one 
species for the genus, namely, Solmundella bitentaculata (Quoy et Gaimard), 1833. 
Under that name all the Solmundelle taken by the ‘Valdivia’ on her long cruise 
(1898-1899) in the North Atlantic, South Atlantic, Antarctic, and Indian Oceans have 
been placed. 
Prof. Maas, on the other hand, recognises two species, S. bitentaculata and S. 
mediterranea (Joh. Miiller), 1851. The latter species Maas (1906) has also recorded 
from the Antarctic, where it was taken by the ‘ Belgica.’ 
The differences between the two species, according to Maas, are the shape of the 
umbrella, colour, and the number of sense organs. S. bitentaculata has a rather high 
conical umbrella, with its apex above the exit of the tentacles, and the fully grown 
adult has sixteen to thirty-two sense organs. SS. mediterranea has a rather flat-topped 
umbrella, not usually extending above the level of the exit of the tentacles, and the 
sense organs do not exceed eight in number. 
Dr. Bigelow (1909) points-out that the number of sense organs would be the best 
character to select for the distinction of the two species. SS. bitentaculata, however, 
passes through a stage with eight sense organs, and the number increases with age, so 
that at an early stage it resembles S. mediterranca. 
I became familiar with S. hitentaculata in Prof. Herdman’s collection of Meduse 
from Ceylon, and after a prolonged second examination of the Solmundelle in the 
‘Discovery’ collection, I came to the conclusion that S. mediterranea is a distinct 
species. About twenty of the largest adult specimens in the ‘ Discovery ’ collection 
were specially examined for the number of sense organs. I could not find more than 
eight, and they are distinctly adradial. S. bitentaculata of a similar size would have 
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