392 Transactions. 



whereas in the young forked chaeta the shorter limb is hollow ; so possibly 

 the suggested explanation is not the true one. In the anterior segments 

 of this young worm I find no forks. 



The gill is " bipinnate," consisting of a relatively stout axis, bearing 

 about 6 pinnae along each side, each pinna carrying a double series of 

 slender pinnules (fig. 6). The number of the pinnae and the size of the gill 

 decrease at each end of the animal. 



The dimensions of the worm vary from 14 mm. by 4 mm. with 24 

 segments in the specimen (e) to 57 mm. by 12 mm. with 34 segments in 

 specimen {h). The more usual size, however, of the above individuals 

 is 40-45 mm. by 10 mm. with 30-33 segments. 



I have examined specimens from the following localities : (a) D'Urville 

 Island, Cook Strait ; coll. Captain F. W. Hutton. (&) Wellington (2 indi- 

 viduals) ; coll. Captain F. W. Hutton. (c) Lyall Bay, Wellington ; coll. 

 Miss Mestayer. {d) Orepuki, Southland ; coll. G. E. Howes, (e) Oft Otago 

 Heads, 100 fathoms : coll. W. B. Benham. (/) Stewart Island; coll. 

 E. Waite. [g) Stewart Island ; coll. W. Traill. {h) Chatham Island ; 

 coll. Miss S. Shand. 



Remarks. — It seems to me probable that Baird's species, C. spectabilis, 

 is identical with this. Baird* himself notes that it resembles both the 

 above and Grube's C. egena. Quatrefages suggested that his species was 

 identical with Grube's C. egena.f It would be better to drop this latter 

 name entirely. It was found, according to Quatrefages, in a bottle with- 

 out any indication of its locality. The diagnosis as quoted by him seems 

 to me insufficient to settle its identity, the only important feature being 

 the simplicity of the chaetae. 



C. pmnata Moore, { from the south coast of California, has also non- 

 serrate chaetae, with an obsolescent spur ; but a few of the chaetae show 

 minute traces of serrations. The worm is altogether smaller, but in many 

 respects seems related to the present species. 



Fam. Nereidae. 

 Cheilonereis peristomialis Benham, " Endeavour " Polycliaeta.% 



I obtained the first specimens of this peculiar Nereid in 1899, from 

 trawlings from the s.s. " Plucky," and I wrote an account of it at the 

 time, which has not been published. The worms were found in the upper 

 whorls of a large Gastropod (? Neptunea) inhabited by a hermit crab. 

 Since that date, however, a closely allied species has been described from 

 thie Pacific coast of North America by Harrington and others||, under 

 the name Nereis cyclurus. The New Zealand species turned up in the 

 " Endeavour " collection. 



The striking feature of the new genus is the great development of the 

 peristomium. the ventral and lateral portions of which are much pleated, 



* Ba.ird, Joum. Linn. Soc, x, 1868, p. 234. 



t Grube, Beschreib. Nexi. od. wenig. bekannt : Ann., p. 91. 1855. 



J Proc. Acad. Nat. Sci. Philadelphia, 1911, p. 239. 



§ The second part of my account of the " Endeavour " worms has not yet (April, 

 1916) been published by the Commonwealth Fisheries Department. 



II Harrington. Trans. N.Y. Acad. Sci., vol. xvi, 1898, p. 214; H. P. Johnston, 

 Proc. Boston Soc. Nat. Hist., vol. xxix, 1901. p. 400; Moore. Proc. Acad. Nat. Sci. 

 Philadelphia, 1908, p. 343, and in same, 1911,' p. 246. 



