POLYCH^TA— BENHAM. 105 



tooth, whicli is slightly smaller than the others; the liase has also a small lobe on its 

 lower edge below the first tooth. The nncini are simih^r throughout, but on the 

 thorax are larger than on the abdomen. 

 Locality. — 



Connnonwealth Bay, Station 10, 325 fathoms. 

 Remarks. — The worni agrees fairly well witli Malmgren's diagnosis of Sanu/tha, 

 from which it differs in three noticeable features — (1) the form of the j^ros- 

 tomium ; ( 2) the presence of a folded menibrane in place of filamentous 

 tentacles ; and (3) the form of the uncinus. It bears no resenil^lance to the 

 only Icnown Antarctic Ampharetid Samytha (?) specidatrix Ehlers (1913, 

 p. 554). Consequently, a new genus is necessary, which may be defined as 

 follows: — " Ainpharetids with a trilobed prostominal flap; tentacles repre- 

 sented by an invaginable membrane; three pairs of cylindrical gills on the 

 second segnaent ; seventeen pairs of notopods ; uncinus with four paired 

 sub-equal teeth on a broad base. 



Family CAPITELLID^E. 

 Genus Isomastus Gravier. 

 IsoMASTUs PERAEMATUS Gmvier. 

 Gravier (1911), p. 113, pi. VIIT, figs. 88-93; pi. IX, figs. 94-108. 

 Four specimens of this, the only Capifellid known from the antarctic, were 

 gathered, aniongst which a well preserved male measures 42 mm. in length by 2 mm. in 

 diameter anteriorly ; it contains fifty-two segments following the head. There is also 

 a female in the collection. 



Locality. — 



Boat Harbour, Commoixwealth Bay, 3| fathoms (muddy bottom). 

 Distribution. — Admiralty Bay, South Shetlaiids, Petermann (Gravier). 



Family MALDANID^. 

 Genus Ehodine Malmgren. 

 Rhodine intermedia Arividsson. 

 Ardwidsson(1911), p. 11, pi. I, figs. .5-11; ph II, figs. 39-41. 

 R. loveni Willey (1902), p. 276, pi. XLVI, figs. 3-5. 

 R. antarctica Gravier (1906), p. 39, pi. IV, figs. 33-37. 



R. loveni Gravier (1911), p. 125, pi. IX, figs. 110-112; pi. X, fig. 114; pi. XI, 

 fig. 133. 



A single imperfect specimen, consisting of the head, followed by tliirteen 

 chfetigerous segments, and another portion consisting of six posterior segments, measure 

 iir all 35 mm. by 1 mm. in diameter. 



