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DEPARTMENT OF THE NATAL SERVICE 



8 GEORGE V, A. 1918 



It is iuteresting to compare this list with the list of those that have been found 

 in the Vancouver island region. Although this region is somevhat farther north than 

 the Bay of Fundy or the greater part of the gulf of St. Lawrence, it is not subject to 

 the same cold currents, hence the conditions are to some extent comparable. 



In my 1914 paper, 136 species were listed and since then 4 more have been added 

 to the list, making 140 in all. Of these 48 appear as well on the eastern Canadian 

 list. On the west coast, of the families represented, the Sertularidas is the most num- 

 erous, with 41 species, 29 per cent of the whole number, the Campanularidae next with 

 34 or 24 per cent. The Gymnoblastea is represented by 25 species, 18 per cent, and 

 the Halecidse with 16 or 11 per cent. This "is not the order on the east coast. The 

 gymnoblastic species are more numerous than the species of any calyptoblastic family, 

 there being 27 or 24 per cent of the whole number. The Campanularidse with 26 or 

 23 per cent beats the Sertularidas with 24 or 21 per cent and the Halecidfc has only 

 9 representatives or 8 per cent. The Plumularidae, a large family, is represented by 

 only 8 species in each case, and as none of these are common there can scarcely be a 

 circumpolar centre for this family. A table will show this comparison more readily : — 



SYSTEMATIC DISCUSSION. 



With regard to nomenclature nothing need be said in connection with any of the 

 families with the exception of the Sertularidse. This family may well be considered 

 on account of the treatment it has received in Levinsen's paper of 1913.^ It is true 

 that in this paper he introduces no opinions that were not found in his paper of 1893^, 

 but he goes into a much more elaborate defence of these opinions and hence the latter 

 paper has received much more attention than the former. 



In the classification of the Sertularida?, as given in these papers, Levinsen casts 

 all other characters aside and bases his entire taxonomic faith on the opercular appar- 

 atus as a basis for generic distinction. Naturally this throws the synonymy of the Ser- 

 tularidse, not by any means in a settled state, into greater confusion. Broch and 

 Kramp have subscribed to his views but elsewhere they have found little favour when 

 considered in their entirety although certain points have been accepted by a number of 

 authors. 



A lengthy discussion of the system, as expounded in the 1913 paper, will not be 

 attempted here but a few general remarks on the soundness of the arguments deduced 

 seems advisable. 



The argument may be stated as follows: There are individual (zooidal) char- 

 acters and colonial (zoarial) characters. In general the individual characters are 

 better suited for taxonomy than colonial characters therefore all colonial characters 

 should be excluded. Among the individual characters, some relate to the trophosome, 

 some to the gonosome. Those relating to the trophosome are more suitable for tax- 

 onomy than those relating to the gonosome, therefore the gonosome characters should 



1 Systematic Studies in the Sertularidae. 



2 Medusae, Ctenophores and Hydroids of the "West Coast of Greenland. 



