KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 51. N:o |l. 65 
difference between Gersemia arctica and Gersemia fruticosa is, however, unimportant, and 
I consider Gersemia arctica (DAN.) to be a G. fruticosa forma arctica (SARs.). (Pl. T, 
fig. 13.) 
Babe: 
Siberean Sea, Lat. 70” 14' N., Long. 170” 17' O., 21 met., clay (Vega exp., 
Se 1878), MV sp. 
Further distribution: 
Spitzbergen, 475 met. (DANIELSEN, 1887), Barents Sea, 360 met. (DANIELSEN, 1887). 
Forma loricata. 
Gersemia loricata MARENZELLER and Gersemia abyssorum (DAN.) belong to this 
form. I have investigated the type specimens of MARENZELLER and DANIELSEN. 
Gersemia loricata. 
Gersemia loricata, according to KUKENTHAL, is a species which belongs to the genus 
Gersemia (sensu KÖUKENTHAL). The colony is attached to a colony of a Bryozoa. The 
anthocodiae are placed together on a short trunk, and they have a calyx, but are retractile. 
No branches exist; the coenenchym is poorly developed, and an obvious trunk is almost 
wanting. The basal part is strongly developed, and completely covers the substratum 
(the colony of Bryozoa). From this basal part rises the short wart-formed trunk. In 
the basal part there exist numerous, horizontal canals, connected with each other, and 
in the insignificant trunk between the coelenterons are developed large, direct canals. 
The walls between the coelenterons are almost entirely reduced. Instead of a powerful 
trunk, there has been developed a small, short one, but one possessing a strongly deve- 
loped basal membrane. This change in the growth has been produced by statical influences. 
The unimportant substratum cannot receive a large colony. The colonies have adapted 
themselves to this substratum. 
My conception of Gersemia loricata as a form of adaptation and not as a distinct 
species is further justified on a comparison with other specimens of different species. 
In the Swedish collection of Alcyonacea there is to be found a specimen of Gersemia fruti- 
cosa, which very much resembles the Gersemia loricata. (P1. IT, fig. 6.) On a worm tube 
there lies a colony with a short trunk and with a collection of anthocodiae. The basal 
part covers the tube. The anthocodiae are large and powerfully armed. In this case 
a few low trunks could be found, connected with the basal membranes. This can also 
be found within Gersemia loricata. As with this latter, the retraction of the anthocodiae 
is increased by the poor development of coenenchym in the trunks and in the branches, 
and a calyx is produced. The anthocodiae are large and are placed close together, all of 
which favours the production of a calyx. 
In Gersemia clavata var. truncata, the same conditions can be very clearly noticed, 
t00: (PL IL; fig. 8.) 
The number of specimens of G. loricata, too, have rapidly increased. KUKENTHAL 
(1910) and BrRocH (1912) describe such specimens. When compared with the specimens 
EK. Sv. Vet. Akad. Handl. Band 51. N:o 11. 9 
