974 MB. W. M. THOMSON ON A BRANCHIATE [Dec. 18, 



2. An Account of a Large Branchiate Polynoid from New 

 Zealand, Lepidonotus giganteus Kirk. By W. Malcolm 

 Thomson, B.A. (N.Z.). With an Introduction by 

 Professor W. Blaxland Benham, D.Sc, M.A., F.Z.S., 

 Otago University. 



[Received November 19, 1900.] 

 (Plates LX.-LXII.) 



Introduction. By Prof. Benham. 



In introducing to the zoological world a new author, I think it 

 is only just, both to members of the Society and to my pupil, 

 Mr. Thomson, to state that, though the paper has been written 

 and the drawings executed by him, I have throughout constantly 

 supervised his work, so that I can confirm all his statements of 

 fact, to which, too, I have here and there added a note. 



In the course of an examination of a collection of Annelids 

 obtained during a recent experimental trawling expedition, carried 

 out by the Fisheries Department of the New Zealand Government — 

 during which provision was generously made for the collection of 

 zoological material, — I had occasion to identify a large species of 

 Lepidonotus, the subject of the present paper. I soon discovered 

 that this Lepidonotus giganteus of Kirk [8] had been previously 

 described under the name Aphroditu squamosa by Quatrefages 

 many years before ; and a question arises as to the strict application 

 of the laws of nomenclature. 



The commonest Polynoid on the coasts of Britain is L. squam- 

 atus L. ; and it appears to me that on the grounds of clearness and 

 convenience — which, after all, are the foundations of any system of 

 nomenclature — it would be desirable to depart in this instance from 

 the strict letter of a law which, if applied, might lead to some 

 confusion between the old established L. squamatus L. and the 

 New Zealand species L. squamosus Q. 



It is true that in faunistic accounts these two names would 

 probably never actually clash, for the British species does not occur 

 on the coasts of New Zealand. But it is not impossible that 

 L. squamosus may occur in Arctic seas, side by side with L. squam- 

 atus ; for in a collection of Polynoids made within the Arctic 

 circle, and handed to me by Prof. D'Arcy Thompson (for identifi- 

 cation — which, however, I had to return to him unidentified, on 

 leaving Oxford), I remember a large specimen of about the same 

 size and colour as the subject of the present note. But as I have 

 no literature here upon Arctic Annelids, I am unable to ascertain 

 whether the Arctic species is identical with our Southern form ; 

 yet, if the " Bipolar Theory " be true, it is not impossible that it 

 may be : then confusion between the two names would arise. 



I have therefore retained the name given by Kirk, who 



