Pdychaeia.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 237 



No doubt the laws governing the distribution of marine and terrestrial annelids 

 are very different. Most, if- not all, of the polychaets give origin to a pelagic larva, 

 which will be affected by the " West-wind Trift," and so spread round the antarctic 

 seas ; yet certain resting-places would be necessary, one would imagine, for the 

 completion of their development. 



How long can a pelagic larva live before it undergoes metamorphosis ? Can it 

 withstand for any period of time the buffeting of the tempestuous southern seas, 

 or escape for long the attacks of fishes and other enemies during its floating existence 

 on the surface of the sea ? When answers to these questions are available we shall 

 be better able to utilise these annelids in any discussion on the previous existence 

 of an Antarctic continent. 



I have not thought it necessary to give a detailed account of the species, for 

 the majority have been fully described and figured by Ehlers in the two contributions 

 on " Neuseelandische Anneliden " published in 1904 and 1907 ; and to any one 

 studying this group of animals these memoirs are indispensable. I have confined 

 myself, therefore, to measurements and details of coloration, with a note on the 

 habitat, and so on. 



For the same reason, I have not in all cases given an absolutely complete 

 synonymy or bibliography, but have included all that is essential for identifi- 

 cation and reference. 



Fam. APHRODITIDAE. 



Lepidasthenia, Malmgren, 1867. 



Lepidasthenia comma, Thomson. 



1901. Polynoe comma, Thomson, Trans. N.Z. Inst., xxxiv, p. 241. 1907. Lefi- 

 dasthenia comma, Ehlers, Neuseel. Annel., ii, p. 6. 



This long, narrow, scale-covered worm measures 73 mm. in length by 4-5 mm. 

 over the body and 8*5 mm. across the parapodia, with 84 segments. The elytra 

 cover the dorsal surface of the body completely in the present specimen ; they are 

 grey, darker at the mediad margins, fading towards the outer, with scattered 

 darker spots ; the anterior ones are suffused with russet near the mediad margin. 



The species has only been found in the tubes of Terebellids ; in this case Thelepus 

 plagiostoma was its protector. 



Locality. — Auckland Island : shore of Masked Island, Carnley Harbour ; 

 (W. B. B.). 



Distribution. — The species is confined to New Zealand shores. 



Fam. SYLLIDAE. 

 Sylms (Savigny, 1809), emend. Ehlers. 

 Syllis closterobranchia, Schmarda. 



1861. S. closterobranchia, Schmarda, " Neue Wirbellose Thiere," I, ii, p. 72. 

 1904. *S. closterobranchia, Ehlers, Neuseel. Annel., p. 19, pi. iii, figs. 1-4. 



This small worm was found under stones, amongst the tubes of Nereis aus- 

 tralis. The dorsal surface of the body is now a pale yellowish-brown anteriorly. 



