POLYCHiETA. — BENHAM. 225 



increase in size. It is true that there may be an increase in 

 number of filaments by one over a variable and inconstant 

 region of the body, but such increase seems to me to be 

 a mere variation, and one knows it to occur in several species 

 in which the gills extend over a long portion of the worm. 



Locs. — East coast of Flinders Island, Bass Strait. 



Entrance to Oyster Bay, Tasmania. 



Oyster Bay, Tasmania, 20-40 fathoms. 



Ten miles north of Circular Head, Tasmania. 



Breaksea Island, Port Davy, Tasmania. 



North of Cape Borda, Kangaroo Island, 40 fathoms. 



Sub-Family ONUPHIDIN^. 



Genus Hyalinoecia, Malmgren. 



Hyalinoecia tubicola, Muller. 



Nereis tubicola, Muller, Prodromus Zool. Dan., 1766, jd. 217. 



Onuphis tubicola, Audouin & Milne-Edwards, Ann. Sci. 

 Nat., xxviii., 1833, p. 225. Id., Ehlers, Die Borsten- 

 wiirmer, 1864-68, p. 297 (with synonymy). 



Northia tubicola, Johnston, Cat. Brit. Mus., 1865, p. 136. 



Hyalinoecia tubicola, MTntosh, Chall. Rep., Zool., xii., 

 1885, p. 335. 



Three individurJs in their transparent tubes, two of which 

 measure 108 mm. by 5 mm. ^.t the broader end and 4 mm. 

 at the other : the third is rather shorter. 



The worm removed from the tube is 50 mm. in length ; it 

 consists of a head with 64 chsetigerons segments ; another 

 is 75 mm. in length ; the third is 55 mm. In this last the 

 tentacles were stretched to the fullest, so were easily 

 measured. 



I suspected that the worm would be H. benthaliana, 

 MTntoshi, and although his account is not very full and is in 

 some respects unsatisfactoiy — for instance, he gives no 

 measurements — after comparing the worms with the various 

 accounts of the European specdes, I have no doubt that it is 



1. M'Intosh— Chall. Rep., Zool., xii., 1885, p. 339. 



