8 IVAR ARWIDSSON, SYSTEMATIC NOTES ON SOME MALDANIDS. 



whole animal, the species has 22 setigerous segments, besides 1 posterior segment with- 

 out setae. It may also be mentioned that the posterior, lower edge of the anal cup is 

 smooth except for a notch in the middle line. There are neither ocelli nor any colour on 

 the anterior end. The uncini that are developed have 6—7 teeth and several bristles. 



Euclymeninae. 



Leiochonini. 



Genus Leiochone Grube. 



Below two species, viz. L. leiopygos Grube (1860) and L. johnstoni Mc Intosh (1915), 

 are dealt with. As there has been some confusion among the authors concerning these 

 species, I shall first review the whole literature regarding them. 



First I wish to draw attention to the fact that one species (L. leiopygos) has brown 

 spöts on the upper side of the anterior end, ocelli chiefly on the lower side, 24 — 25 seti- 

 gerous segments, posterior achaetous segments externally slightly set off and no anal 

 cirri, and that the other species (L. johnstoni) does not possess these brown spöts, has 

 ocelli on the upper side as well, has 19 setigerous segments and anal cirri. 



These are thus very distinct characters, which, however, it has formerly been dif- 

 ficult to state with complete accuracy owing to the lack of suitable material. 



I now pass on to examine the literature connected with this. According to Cuvier 

 (1, p. 212), Leiochone ebiensis (Aud. et Edw.) (2, Pl. 22), was described or rather was to 

 be described in Recherches pour servir a 1'histoire naturelle du littoral de la France 

 (Aud. et Edw.) and the figures (8 — 12) belonging to the species were to be published on 

 a 10 th plate. Figures and description would have belonged to the 3 rd part of the work, 

 which was never issued. 1 If the figures could be found, it is not impossible — assuming 

 that they are not the same as those published låter (2) — that they might afford us a 

 clearer view of the species in question. At present it seems wisest not to use the name 

 (Clymene) ebiensis, and for the following reasons. It has been maintained that fig. 4 e (2) 

 does not represent the posterior end, as, if so, the anal cone would f ollow almost immedi- 

 ately af ter the setae of the last setigerous segment ; on the other hand it has been assumed 

 that the figure refers to a specimen cut off posteriorly. But how are we then to explain 

 (1) that the setae of the last segment (visible in the fig.) are not situated farther back 

 on the segment, and (2) that the hindmost part of the segment bears a great resemblance 

 to the anal cone with the anal papilla? (Cf., for instance, my fig. 19 of L. leiopygos.) 

 It seems to me highly probable that fig. 4 e really represents the anal cone, and why 

 not an anal cone resembling that of L. leiopygos ? If we suppose that the posterior limit 

 of the last setigerous segment is not reproduced in the figure and that the part behind 

 this is not fully regenerated after an earlier mutilation, and that the posterior »ring» 

 is somewhat bent inwards, the resemblance with L. leiopygos is extremely great. The 



1 T. 2 (last part), 1834, contains Annélides. Premiére partie. 



