40 IVAR ARWIDSSON, SYSTEMATIC NOTES IN SOME MALDAN1DS. 



a large one had a few of these on the 7 th setigerous segment as well. Finally 3 large 

 specimens had similar fine setae only on the 9 th setigerous segment. There is thus a 

 considerable variation, which at least so far cannot be connected with a difference in 

 sex, maturity, or other factors. When the anterior setae are numerous the posterior 

 ones seem to be few, and vice versa. 



Mc Intosh (31, p. 342) at first expressed some doubt as to the validity of my spe- 

 cies Caesicirrus neglectus. Låter, however, he mentions it without any reservation 

 (32, p. 161). Still it is really possible that the species has been previously described 

 under a special name (ef. 28, p. 224), as will be seen from the following. 



Euclymene digitata (Grube) Verrill has, according to Grube's description (5, 

 p. 54) of a spec. from Fiume, 19 setigerous segments, 2 posterior achaetous ones, and 7 

 long anal cirri, between which there are a number of shorter ones. Grube' s fig. 5 also 

 shows that the 7 th setigerous segment has parapodia behind the middle ( = Caesicirrus 

 neglectus). The posterior end too, where there may of course very well be a third very 

 slightly developed achaetous segment as in C. neglectus, shows a rather close resemblance 

 to the latter species. But Grube' s description is so brief that at present we cannot 

 say anything definite as to whether Euclymene digitata and Caesicirrus are especially 

 closely connected or perhaps synonymous. It is not impossible, but in that case we 

 must assume, inter alia, that Grube' s specimen was exceedingly contracted. 



Similarly one may suspect that Clymene oerstedii Claparéde 1863 (4, p. 28) from 

 St. Vaast la Houge is more or less closely connected with C. neglectus. It is true that 

 Claparédes fig. 6 shows anterior parapodia only in the first 5 setigerous segments; 

 and in addition only 16 setigerous segments, but the former may of course be due to 

 a certain incompleteness in the drawing and the latter to a previous mutilation of 

 the posterior end, especially as Claparéde has 22 segments altogether or the same 

 number as in Caesicirrus neglectus. According to St. Joseph 1894 (16, p. 137), the spe- 

 cies has 16 setigerous segments (Cotes de Dinard) or 19 (Concarneau); the former state- 

 ment agrees with that given by Claparéde, and may of course be interpreted in the 

 same way. If, however, the species possesses 19 setigerous segments, there is complete 

 agreement with C. neglectus in this respect, even if perhaps Claparéde has not observed 

 a third posterior achaetous segment, which ought to be present with this assumption, 

 but has included the posterior ring in front of the anal funnel. But of course the 19 

 setigerous and the 2 posterior achaetous segments may also be present, in that case 

 agreeing entirely with Grube' s description of his Cl. digitata. Further it is import ant 

 to point out that Cl. oerstedii possesses distinct ocelli (but stronger and reaching 

 farther back than in C. neglectus); moreover the uncini are rather like those in C. neg- 

 lectus, and finally the species has 7 longer anal cirri, figured, however, as being of 

 equal length, and, between these, smaller d e n t a t e cirri. As, finally, the species was com- 

 mon in shallow water, there is a good deal to make one suspect that we have here the 

 same species as Caesicirrus neglectus. In order to decide this question we need a fresh 

 investigation of Claparéde's species, in which special attention ought to be paid to 



