780 J. H. ASHWOETH. 



described, and no diameter is mentioned hy which their 

 ."■pecies may be detei mined. Ehkrs' diagnosis of the 

 Californian woims rests sokdy npon a diameter wliicli is 

 very variable and almost useless for distino-uisliing species. 

 A re-examination of what are probably the same specimens 

 proves them to be A. claparedii, and this species has also 

 been recorded from another point on the west coast of the 

 United States (pp. 772 — 774). Incidentally it may be men- 

 tioned that specimens of A. claparedii from the west coast 

 of North America almost invariably beai" only twelve gills 

 either on one or both sides, while Neapolitan specimens have 

 usually the full number (thirteen pairs). 



A. assimilis may be regarded as the characteristically 

 southern species of the genus. Adult typical specimens are 

 recorded from several points in the extreme south of America 

 and from South Georgia. A new variety (var. affinis), 

 differing from the type only in the number of chfetigerous 

 segments, is now recorded from Otago Harbour (New Zea- 

 land), the Macqnarie Islands, and the Falkland Islands. 

 Post-larval stages of the variety have been taken off the 

 Falklands and near Uschuaia, in the Beagle Channel. 



X. Literature. 



ISfil. SciiMARDA, L. K. — 'Neuc Wirbellose Tliiere,' Baiul i, p. 51, Leipzig, 



18G1. 

 1878. Grube, E.— " Annclicien-Ausbeut.c S.M.S. Gazelle," ' jMonat&ber. d. K. 



Akad. d. Wissenscli. zu Berlin, aiis dem Jalire 1877,' pp. 511, 554, 



Berlin, 1878. 



1893. Beniiam, W. B. — 'Journal Marine Biol, Associalion,' New Scries, 

 vol. ill, p. 48, 1893. 



1897. EiiLEUS, E. — '• Polyclioetcn," ' Ilaniburi^er Mai^alliaoniselic Saniniel- 



rcisc,' pp. 103, 101, Hamburg, 1897. 



1898. Gamble, P. W., AND Asiiworth, J. II.— 'Quart. Journ. Micr. Sci.,' 



vol. xli, p. 1,1898. 



1899. Kauvef,, p. — ' Meinoircs dc la Socictc iiationalo de.s Sciences nalurellcs 



et mallicinatiques de Cherbourg,' tonic xxxi, p. 178, Cherbourg, 

 1899. 



