POLYCH^TA BENHAM. 109 



The 26 bundles of capilliform chactse project for 16-25 mm. beyond the translucent, 

 firm, jelly-like investment of the body, which is here greyish, not yellowish-brown as 

 described by the previous authors. The chsetse, which are covered with mud, are 

 accompanied by long-stalked clavate papillae. 



Localities. 



Station 10, 325 fathoms (one). 

 Station 12, 110 fathoms (two) 



Distribution. Port Charcot, South Shetlands (Gravier); Kaiser Wilhelm II Land, 

 South Victoria Land (Ehlers), 



Family SABELLID^E. 

 POTAMILLA Malmgren. 

 POTAMILLA ANTARCTICA Kiriberg. 



Laonome Antarctica Kinberg (1866), p. 354. 



Laonome antarctica Ehlers (1897), p. 135 ; (1901), p. 216. 



Potamilla antarctica Gravier ( 1906), p. 59, text-figs. 38-43. 



Potamilla antarctica Gravier (1911), p. 144, pi. XI, figs. 137-141. 



Potamilla antarctica Ehlers (1913), p. 575. 



Potamilla antarctica Fauvel ( 1916), p. 474, pi. VIII, figs. 4-7. 



Of this species, so widely and abundantly distributed through the antarctic seas, 

 a large number were forwarded to me. They may be grouped for convenience of reference 

 into two lots; partly from their geographical range, and partly from the size of the 

 individuals. 



Group A consists of small individuals from 25-40 mm. in length, exclusive of the 

 gills. These occur on the shores of Macquarie Island. They agree in dimensions, as 

 well as in external features, with the worms described by Ehlers, Gravier,* and Fauvel, 

 which has hitherto been regarded as the typical condition of the species. 



Group B contains much larger worms, attaining lengths ranging from 72 mm. up 

 to 230 mm., exclusive of the gills. These come from Commonwealth Bay, at various 

 depths; and the larger ones exceed in size the largest specimen, of which the dimensions 

 have hitherto been recorded, namely, that mentioned by Ehlers as being 170 mm. in 

 length, obtained from South Victoria Land. 



From their much greater dimensions I expected that these would prove to belong 

 to a different species, but after examining them from every anatomical point of view, 

 I came to the conclusion that there are no features that distinguish them from the more 

 typical specimens under Group A, other than their size. 



* Gravier describes the species as if it were pew, affixing his own name after it. 



