46 ARVID R. MOLANDER, ALCYONACEA. 
in the same species. I now wish to advance some views, which, I hope, will decide the 
nature and genesis of the calyx. 
1) Young specimens of different species, for instance, Gersemia (= Funephthya 
(pars), KÖKENTHAL) fruticosa, G. clavata var. truncata, and others, have, as a rule, in 
proportion to their size, vigorous development of spicules in the trunk and the antho- 
codiae. 
2) Since the development of the polyps takes place, as a rule, more rapidly than 
that of the trunk, and since, too, the poorly developed coenenchym of the colony makes 
the retraction of the anthocodiae impossible from purely mechanical reasons, the result 
is a production of a calyx. 
3) Certain colonies, on account of adaptation to their substrata and of other bio- 
logical reasons, have suffered a great change of shape, with a strongly marked reduction 
of the coenenchym in trunk and branches, as, for instance, Gersemia fruticosa forma 
loricata (MAR.). In consequence, there often appears calyx. In this case, however, a 
retraction can be noticed, too, especially when the number of polyps is small and when 
they are scattered (Gersemia fruticosa forma membranea). 
4) Even in well-developed specimens a calyx may exist. It is not, however, so 
constant and appears principally in specimens with profuse armature in the anthocodiae 
and in the bark of the coenenchym. As this armature, even in the same species and even 
in the same individual, may vary very much, the natural consequence is a great variation 
in respect to the occurrence of calyx. 
5) The spicules in the lower part of the anthocodiae and in the bark of the 
coenenchym which surround the lower part of anthocodia, are the chief decisive 
factors as regards the formation of a calyx, but a strong armature in the upper part of 
the anthocodiae may also produce a calyx, as, for instance in Gersemia fruticosa var. rigida, 
with its long and narrow spicules. The introvertion of the upper part of the anthocodia 
is increased, even rendered impossible, but the lower part of the anthocodia includes the 
possibly retracted upper part of the anthocodia and also produces a strongly developed 
calyx. This, however, cannot always prevent a retraction of the anthocodiae as the 
number and size of the spicules vary in different species. 
6) An insignificant armature of spicules in the anthocodia effects their complete 
retraction; Gersemia rubiformis, for instance, which has a sparse development of spicules 
in the anthocodia, is mostly devoid of the calyx. 
7) In all Gersemia-species (sensu MOLANDER), possibly with the exception of the 
last-named, there exists a calyx. 
Besides the facts regarding the calyx, I also wish to advance some other points of 
view to prove the unsuitability of retaining Gersemia (sensu KUKENTHAL) as a separate 
genus. 
8) The direct canal system, assigned to Gersemia (sensu KUKENTHAL), develops 
as a consequence of the crowding between the coelenterons, which is particularly the case 
with young specimens, in consequence of the more rapid development of the polyps, 
than of the coenenchym, in the trunks and branches. When the colony is well developed, 
the direct connection disappears, and in other cases it is only retained as long as the 
