10 IVAR ARWIDSSON, SYSTEMAT7C NOTES ON SOME MALDANIDS. 



Grube's doubt whether the anterior and posterior part of the type specimen really 

 belonged together. 



Two years earlier Mc Intosh had described a single Leiochone-sipecimen, which 

 he called Clymene ebiensis Atjd. & Edw. (15, p. 103); this form seems, says St. Joseph, 

 to resemble his L. clypeata closely according to the description, b ut in the figure 1 

 he counts 22 setigerous segments and 6 posterior achaetous segments ( »en tout 30 seg- 

 ments, dont le buccal, les 6 anteanaux et 1'anal sont achétes»). For this reason St. Jo- 

 seph does not venture to identify his L. clypeata with the Cl. ebiensis of Mc Intosh. 

 Both Mc Intosh and St. Joseph seem, however, to have assigned to the specimen in 

 question one (developed) setigerous segment too much; at least my view of Mc Intosh' s 

 fig. 1, which is rather indistinct with regard to the 8 th setigerous segment, is that there 

 are 21 setigerous segments developed. Of the 6 posterior segments, which are stated to 

 be achaetous, the 4 anterior ones have more or less distinct remains of parapodia. It 

 now seems to me very probable that these 4 segments are the hindmost setigerous seg- 

 ments, whose setae, after a mutilation of the posterior end, are not yet developed. In 

 other words the specimen of Mc Intosh would have 25 setigerous segments and 2 posterior 

 achaetous segments; if one further considers the general structure of the part behind 

 the last setigerous segment (note the absence of anal cirri), the agreement with L. leio- 

 pygos ( = L. clypeata), as conceived by me, is complete. Nor is Mc Intosh' s description 

 in other respects incompatible with this view. 



Thus at that time Mc Intosh and St. Joseph had before them in reality one and 

 the same species, L. leiopygos (Gr.). Leaving aside some statements of minor importance 

 — for a more complete survey of the literature concerned see Arwidsson (24) and Mc 

 Intosh (31) — I here pass on to Mc Intosh's »Monograph of the British Marine Anne- 

 lids». Here are included, among others, L. ebiensis (with? L. clypeata among the syno- 

 nyms!) and L. clypeata (with L. polaris Théel as a synonym!). Mc Intosh's »L. 

 clypeata » has a cephalic plate and can thus not have any thing in common with L. clypeata 

 St. Joseph ( = L. leiopygos). It is even exceedingly uncertain whether Mc Intosh really 

 has based his description on a Leiochone-sipecies (if so, with a cephalic plate); the absence 

 of a projecting anal cone may be pointed out, inter alia. The uniting of the species in 

 question with L. polaris Théel, which is distinguished by only one anal cirrus (though 

 it certainly has a cephalic plate), seems to me more than premature and Mc Intosh 

 points out himself that there are differences between his form and the typical L. polaris. 

 He finally adds: »Further work in the Maldanids may considerably modify published 

 views. » ( ! ) To this it may be remarked that a most detailed description of L. polaris 

 (based on at least 20 spec.) was given by me in 1907 and thab Mc Intosh has not even 

 tried to put forward any arguments, why this description ought to be disregarded. If 

 this procedure were to be generally followed, the result of descriptive systematization 

 would be complete chaos. 



As to L. ebiensis of Mc Intosh (31), it is obvious that in describing this species 



1 St. Joseph seems not to have found in Mc Intosh's description any statement as to the number of se- 

 tigerous segments, although it contains the information that the 23 rd segment [= 22 nd setigerous segment] is the 

 last setigerous one. 



