ZOANTHARIA 



Of the species already known the following are described in the present paper. 



Epizoanthus incrustattis, pagnriphilus, abyssorum, glacialis, rosens, norvegicus and erdmanni. 



Isozoanthns arborescens and 



Parazoanthus anguicomus. 



Further, some anatomical details of Parazoanthus dixoni are also given here. 



The new species are: 



Epizoanthus danielsseni, lindahli, beerenislandicus, koreni. 



Isozoanthus bulbosus, danicus, magninsulosus, multinsulosus, davisi, ingolfi, dubius, islandicus. 



Parazoanthus haddoni. 



All told the descriptions thus comprise 22 species, showing that the northern and arctic 

 Zoanthid fauna is not so poor as was formerly thought. 



In the present paper I do not occupy myself very much with the geographical distribution, 

 as I shall return to this subject later on when dealing with the Ceriantharia and Actinaria of the 

 same regions. Along with this I propose to make a more detailed comparison between the Actinian 

 fauna of the arctic and antarctic waters. It is worth noting, that though the number of known species 

 from these regions has increased considerably, no representatives of the microcnemic Zoanthidae have 

 been found there. The occurrence of the new genus Isozoanthus in both of these zones is also 

 worthy of note, though it is not impossible, that this genus like the genera Epizoanthus and Para- 

 zoanthus also occurs in the intermediate regions. There seems to be a great difference in the distri- 

 bution towards the north between the genera Epizoanthus and Isozoanthus on the one side and 

 Parazoanthus on the other, the latter not being represented in the true arctic fauna, in which both 

 the first-named occur. Towards the north the genus Parazoanthus seems to be replaced by Isozoan- 

 thus, of which a decidedly arctic species, I. bulbosus, has been met with so high up as north of Spitz- 

 bergen at 81 N. Lat, this being the northernmost place of occurrence of any Zoanthid species. It is 

 as yet too early to foretell, what the conditions are in the antarctic region, but I am of opinion, that 

 they are similar there. The material at my disposal from this region is, however, too limited to allow 

 of any certain decision. The Zoanthid fauna seems to be poorer and to decrease more quickly towards 

 the south, than is the case in the northern waters towards the north. 



Section II. 



Contribution to the systematic classification of the Zoanthidae. 



Among the Anthozoa, at least among the forms generally comprised under the name sea- 

 anemones, there is hardly a group which is so uniform in its morphological characteristics as the 

 Zoantharia (Zoanthidae). The few genera are generally easily distinguished from each other, whereas 

 it is more difficult to separate the species within the different genera. A number of Zoantharia 



species have been described especially in the older literature and almost exclusively from outer 



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