24 IVAR ARWIDSSON, SYSTEMATIC NOTES ON SOM K MALDANIDS. 



Fancy all these different types grouped under one genus, the old Clymene! The diagnoses 

 of species would then of course — as has in the past often been the case — be full of 

 generic characters, while the real specific characters, if included at all, would not appear 

 distinctly. What a relief it would be for the investigator if, on discovering, for instance, 

 a Praxillella-species he could at once sur vev all the described species of this genus 

 without having to review and interpret also the endless series of more or less badly 

 described Clymene-species. Of course in using these more restricted genera we must 

 take care not to include species in wrong genera — which unf ortunately has not always 

 been dul} r observed. An instance of a species being assigned to a genus to which it 

 scarcely belongs, but where it is placed for the present for certain practical reasons, 

 is Microclymene tricirrata Arwidsson; the type for the genus is M. acirrata Arwidsson, 

 and there can be no doubt that these two species are not especially closely related to 

 each other. It is said that on the whole polychaeta are poor in species r but, apart from 

 the fact that a large number of species just in the Euclymenini are still undescribed, it 

 is surely not only the number of species in a genus that determines whether the 

 latter is justified. 



It is of course often a matter of taste whether in certain cases sub-genera are to be 

 preferred to genera. For instance in arranging the species of the genus Nicomache I 

 preferred to propose two sub-genera rather than to create two new genera, and at 

 present I ha ve no reason to abandon this view; it seems, however, as if in certain 

 quarters these sub-genera were disregarded. With regard to the genus Asychis I will in 

 this connection ref er to earlier statements (29, p. 433). 



An eloquent example of the danger of not keeping, as far as possible, the genera 

 in the tribus Euclymenini separate, is offered in the case of Praxilla kerguelensis Mc 

 Intosh. From Mc Intosh's description of specimens, all of which seemingly lacked 

 the posterior end, we may conclude that the species certainly must belong to the 

 Euclymenini, but on the other hand it surely cannot belong to the genus Praxilla (Praxil- 

 lélla) (ef. 24, p. 177). Accordingly when describing an antaretie Praxillella (27, p. 19), 

 which possibly may be identical with a species described by Eulers under the name 

 of Clymene (Praxilla) kerguelensis Mc Intosh, I had of course no right at all — just as 

 little as Ehlers had indeed — to use Mc Intosh' s name. Now Fauvel (33, p. 457), 

 who has re-discovered Ehlers' species, has adopted the name of Mc Intosh as well and 

 calls the species Clymene kerguelensis Mc Intosh. Fauvel writes, inter alia, as follows: 

 « La Clymene kerguelensis Mc Intosh, sensu Ehlers, est parfaitement reconnaissable et 

 le nom de Praxillella antaretica, synonym et plus récent, doit disparaitre ». In other 

 words Fauvel entirely disregards the fact that Mc Intosh's species does not belong to 

 the genus Praxillella, as does certainly the species described by Ehlers, myself and 

 Fauvel. 1 I venture to believe that this confusion would not ha ve taken place, if a 



1 With regard to the identity of the forms treated by Ehlers, myself and Fauvel, we have from Fauvel, 

 inter alia, first the information that his material agrees well with Ehlers' description, secondly that the epider- 

 nial glands stainable with iodine green agree with the conditions in Praxillella antaretica Aewidssox. If, how- 

 ever, we take into consideration the fact that Ehlers' and Fauvel's form has ocelli, contrary to P. antaretica, 

 and a somewhat deeper notch in the posterior part of the cephalic börder, it still seems to be unsettled, whether 

 there is complete identity between my P. antaretica and the form which Ehlers and Fauvel had before them. 





