POLYCH.^TA. — BENHAM 141 



Remarks. — This species is closely allied to the Eastern 

 Pacific species. Harrington found C. cyclurus in association 

 with Hermit-crabs. The present species differs from it in 

 the form of the parapodia both in the atokons and in the 

 epitokous forms. In the atokoiis condition the dorsal ligule 

 has a rounded instead of the sharply pointed tip of C. peri- 

 stomialis, and the notch in which the dorsal cirrus arises is 

 much deeper, owing to the greater height of the basal lamella. 

 The dental formula also, if I understand Harrington's account 

 rightly, differs in that the denticle in V. is present. His 

 account, however, is very obscure. He writes thus :- — 

 " (5) Median dorsal proximal teeth =tMo points, prominent, 

 in an ill-defined ring on proximal basal somite, which is 

 slightly strongest at ventral side." It may be that these 

 " two points " are the two groups of larger denticles in the 

 compartment VI. 



The dental formula given by Izuka for C. shishidoi agrees 

 closely with that in the present species. 



It appears to me that the shght differences between C. 

 cyclurus and the Japanese species C. shishidoi, Izuka, ^ are 

 insufficient for specific distinction. Moore has recorded C. 

 cyclurus from Vancouver Island- and from the C'alifornian 

 coast. ^ Ramsay^"" also describes it from the N.E. Pacific. 

 Harrington's specimens came from Puget Sound. 



The two species are evidently closely alhed, and it is here 

 that the trinominal nomenclature would be useful ; it has 

 not been introduced into Polychset literature, but it well 

 might be. Thus we should have C. cyclurus cyclurus from 

 American waters, C. cyclurus shishidoi from Japan, and C. 

 cyclurus peristomialis from Australasian waters. 



It is perhaps rather dangerous to suggest a new generic 

 title for any Nereid, judging from the disuse of the many 

 names suggested by Kinberg and Malmgren, but the extra- 

 ordinary development of the lower lip differs entirely from 

 anything hitherto described, so far as I can, ascertain from 

 the Hterature accessible to me here. 



1. Izuka — Journ. Coll. Sci. Imper. Univ. Tokyo, xxx., 1912, p. 177. 



2. Moore— Proc. Acad. Nat. Sci. Philadelphia, 1908, p. 343. 



3. Moore— Loc. cit., 1911, p. 246. 



3a. After the MS. had been sent to the Editor I came across Ramsay's 

 account of C. cyclurus (Proc. Zool. Soc, 1914, p. 237), wherein he suggests 

 that the extraordinary development of the peristomium was almost worthy 

 of generic recognition. He draws attention to the " curious homogom))h 

 jalcate setae " which occur in the notopodial bundle of the parapodia in 

 hinder part of the worm. I find in my MS. account, written some 10 

 years ago or more, that these occur also in our New Zealand species. 

 Ramsay also discusses the relation of this species to Alitta virens. 



