58 PENNATULIDA. 



rather variable, but is almost always different shades of red; only Nr. 6 Pr. carinatum* is stated 

 by Danielssen to have been straw-coloured, the calyxes almost white. .For several specimens the 

 colour of the calyxes of the polyps is stated to have been of a brick-colour ; now, however, they are 

 almost quite bleached or only pink; exceptions in this respect are formed by the Swedish specimen 

 Nr. ii and one of those taken by the (Michael Sars (Nr. 10), both being still of an intense brick- 

 red colour. 



By a careful comparison of all the Scandinavian specimens I have not been able to find any 

 difference that might justify a division into several species. The four species established by Danielssen 

 on the material of the North-Atlantic Expedition: Pr. lofotense, armatum, carinatum, and mohni, are 

 each based on only one single specimen; in other words, each specimen found has been made a 

 separate species, although the localities might have advised some caution; scarcely anybody will be 

 able to find reliable specific characters in the (otherwise very careful) descriptions of Danielssen, no 

 more than in his figures, and the specific diagnoses he himself gives, must be rejected by all, who 

 have had any experience with regard to the Pennatulids. The fact is that the differences really 

 found in these four specimens are individual ones, either such as are due to different development 

 and growth (as the number and particular arrangement of polyps and zooids), or such as owe their 

 origin to a casual degree of retraction (for instance, the features that have evidently given rise to 

 the specific name carinatum\ further, that the polyp-calyxes may be narrower, more or less projecting 

 and marked off from the rhachis etc.). That it is injudicious to seek characters for the division 

 of species in such features is immediately seen, when new specimens are found. In this respect I 

 may refer to the fact that the two specimens found by Dr. Appellof (Nr. 3 and 7 of the table), when 

 judged in the same way as has been done with those of the North-Atlantic Expedition, would of 

 necessity have to be established as two new species, neither of them agreeing exactly with any of the 

 species of Danielssen, but being more or less closely related to each of them and being, besides, provided 

 with something new. Grieg, to be sure, has seen this (at all events with regard to one specimen, 

 comp. Norges Penn. p. 21), but he has also seen that it would be dangerous to create new species; the 

 more so since the Swedish specimen (Nr. n of the table), which Grieg has also had the opportunity 

 of seeing, might as well lay claim to the same title, as it cannot be said absolutely that it seems to 

 be qiiite similar to the type-specimen of Pr. mohnn ; only with the specimens of Appellof in mind 

 could there be from Grieg's standpoint any question of referring it to Pr. mohni*. But when it is 

 understood that /V. mohniv may assume so many different shapes, the necessary consequence will be 

 the incorporation of the three other forms of Danielssen into the same species. I am therefore quite 

 persuaded that every one, who can now inspect and compare all the Scandinavian specimens I have had 

 at my disposal, will arrive at the same view with regard to their specific identity. Strange to say, no 

 comparison with the species Pr. thomsoni seems hitherto to have been attempted; at all events this 

 species is not mentioned at all by Danielssen or Grieg; nevertheless, the agreement between the 

 Sandinavian forms and this one is in all essential features so close, that I think myself fully justi- 

 fied in using the specific name of Kolliker. Also, the features of the inner structure mentioned by 

 Kolliker (Monogr. p. 371), have been found by me in the Scandinavian specimens I have examined 

 in this respect. Thus, I find the radiate canals, to which Kolliker especially calls our attention as 



