ZOANTHARIA 



Danielssen's E. norvegicus. In his paper of 1883, PI. 8, fig. 6, an ilhistration of this variety is 

 given. Though it is, of course, very difficult to settle the question without being in possession of 

 the original specimens, if they exist, the variety undoubtedly belongs to a Parazoauthus species. 

 Verrill's figure has, namely, a fairly strong resemblance to the colony figured by me on PI. i, fig. 19, 

 collected at St. 2245 U. S. F. C. together with the typical E. americanus (incrustatus) and determined 

 as such, but which on closer examination proved to be a Parazoauthus species and in my opinion no 

 other than P. anguicomus. Lastly, in the year 1885 Verrill described another carcinom-forming 

 species, Epizoanthus abyssorum, dredged during the Albatross Expedition in 1884, and mentioned at 

 the same time a free variety of this species (probably a new species). Though Epizoanthus abyssorum 

 has evidently a more southerly distribution than the other North American species mentioned, I 

 prefer to deal with it here for comparison between E. incrustatus and E. paguriphilus. I would point 

 out, however, that I have had very little material of the North American species at my disposal, this 

 being the reason why these are not dealt with in greater detail here, as also because a further 

 criticism of the species based on the literature is fairly unremunerative. A revision of the collected 

 material of the Zoanthidae forms will certainly prove, that the number of Zoanthid species is also on 

 this coast not so small as seems to appear from the literature. I have not thought it necessary to 

 give a complete list of the literature of these three species here. Up to 1891 such a list has in any 

 case been given for both of the first-named species in Had don and Shackle ton's paper (1891). 



In the >'ear 1890 the number of known northern and arctic Zoanthidae species was almost 

 doubled by Danielssen's description of the material collected during the Norwegian North Atlantic 

 Expedition. The new species occurring are Epizoanthus roseus, E. arborescens, E. glacialis and 

 Mardol erdmanni, the last of which was j^roved by Had don and Shackle ton's investigations 

 (1891) to belong to the genus Epizoanthus. In 1887 (p. 316) Mortensen was of opinion, that he had 

 found Zoanthus sulcatus and couchii in the Limfjord, a determination however which must be erroneous 

 at least as regards the latter, as this species according to Haddon and Shackleton is an Eisizoanthus 

 species, whereas Mortensen's form appeared to belong to a genus Isozoanthus founded by me. Lastly, in 

 1905 Carlgren mentions from Finmarken, besides E. erdmanni, also Isozoanthus arborescens, for which 

 he later set up the above-named genus, Isozoanthus, forming a link between the genera Epizoanthus 

 and Parazoanthus. 



Thus, when I began my paper on the northern and arctic Zoanthidae, altogether some ten 

 species of these had been described previous!}-, many of them, however, very incompletely and mainly 

 according to the external features. In 1890 Danielssen certainly gives anatomical descriptions of 

 his new species, but in many respects these are not to be trusted and are of small use for the 

 identification of the .species. Of far greater importance is Haddon and Shackleton's paper on the 

 British species of Zoanthidae. We find here a good anatomical description, which however in some 

 respects might have been somewhat more comprehensive. As this is the only efficient work dealing 

 with the Zoanthidae of the North European coasts, I may refer to it specially, as it also contains an 

 account of the most important literature on the Zoanthidae up to 1891. Of the species dealt with in 

 the sequel, however, only E. incrustatus, E. paguriphilus and Parazoauthus anguicomus are described in 

 detail in the above-named paper. 



