KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 51. N:o ll. 15 
Connection between the Ramification and Canal System of the Colony in the case 
of the Genera Gersemia and Eunephthya. 
In the genus Gersemia, G. rubiformis represents the most orinigal type, as regards 
the building up of the colony, most nearly resembling the family of Alcyoniidae. The 
short, coarse branches, which are strongly expanded at the point, form, as it were, cush- 
ions covered with polyps. The branches unite together closely and almost completely 
cover the trunk. The solenia consists of numerous indirect canals and cell-strings. The 
direct canals are rare or altogether absent. From this specimen, with the closely allied G. 
uvaeformis and G. clavata, development tends in the direction of finding space for a large 
number of polyps, with the greatest possible economy of material. This has produced the 
strongly branched forms, G. fruticosa and G. mirabilis, which are poorer in coenenchym, 
and, further, the Funephthya species. Within G. fruticosa and G. mirabilis, the direct 
canals are numerous, at least within G. fruticosa. The transition in external morpho- 
logical respects from Gersemia to Eunephthya is provided by G. mirabilis, and, in a still 
greater degree, by G. spiculosa and G. japonica. G. marabilis has, on the larger bran- 
ches, smaller, shorter ones, which, at the points, bear from 4 to 6 polyps. &G. spiculosa 
and G. japonica also exemplify simplification, as the shaft of the minor branches are 
shortened, and the number of the polyps on every branch is less, the outer coenenchym 
in the branches being further Jiminished, and the power of retraction reduced in a still 
greater degree. From this point it is easy to follow the development to the Funephthya 
forms, first of all £. glomerata, with grouped, close-lying distribution of polyps along 
a short branch. A further step forward as regards ramification is marked by the um- 
bellate types, where every large branch is resolved into a number of minor, umbrella- 
like minor branches bearing polyps. Simultaneously the canal system undergoes the 
change mentioned above. From what has been said, it may be gathered that the genus 
Eunephthya (sensu MOLANDER) is evidently developed from Gersemia (sensu MOLANDER), 
but the difference between them is, I consider, enough to allow them to be considered 
as distinct genera. 
Apart from the reduction in the coenenchym of the trunk and the branches, which 
has been the result of the ramification of the Zunephthya (sensu MOLANDER), the indirect 
connection has been retained. Tf, as is assumed by KUKENTHAL, the direct canals denote 
a higher form of development, produced by reduction in the coenenchym, these ought 
therefore to be very numerous within Funephthya. That this is not the case merely shows 
—as I have already pointed out — that the direct canal system can not be looked upon 
as system-characterising and does not arise as a consequence of a diminution in the outer 
coenenchym in trunk and branches of colonies. It is probable that the indirect canal 
system is the original for the fam. Nephthyidae, and future investigations will very likely 
make clear its nature, with regard to the other genera of this family. 
If the genus Gersemia MARENZ. (sensu KUKENTHAL) had been homogenous, we 
ought, consequently, to look for a direct canal system, as, according to KUKENTHAL, it 
has developed directly from Eunephthyae alcyoniformes (sensu KUKENTHAL), and is a con- 
