P0LYCH2ETA—BENHAM. 
] 05 
tooth, which is slightly smaller than the others; the base has also a small lobe on its 
lower edge below the first tooth. The nncini are similar throughout, but on the 
thorax are larger than on the abdomen. 
Locality .—- 
Commonwealth Bay, Station 10, 325 fathoms. 
Remarks. —The worm agrees fairly well with Malmgren’s diagnosis of Samytha, 
from which it differs in three noticeable features—(I) the form of the pros- 
tomium; (2) the presence of a folded membrane in place of filamentous 
tentacles ; and (3) the form of the uncinus. it bears no resemblance to the 
only known Antarctic Ampharetid Samytha (?) specula,trix Elders (1913, 
p. 554). Consequently, a new genus is necessary, which may be defined as 
follows :—Ampharetids with a trilobed prostominal flap; tentacles repre¬ 
sented by an invaginable membrane; three pairs of cylindrical gills on the 
second segment ; seventeen pairs of notopods ; uncinus with four paired 
sub-equal teeth on a broad base. 
Family CAP I TE LLIDCE. 
Genus Isomastus Gravier. 
IsOMASTUS PERARMATUS Gmvief. 
Gravier (1911), p. 113, pi. VIII, figs. 88-93; pi. IX, figs. 94-108. 
Four specimens of this, the only Capitellid known from the antarctic, were 
gathered, amongst 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, Commonwealth Bay, 3-| fathoms (muddy bottom). 
Distribution. —Admiralty Bay, South Shetlands, Petermann (Gravier). 
Family MALDANIDAE. 
Genus Rhodine Malmgren. 
Rhodine intermedia Anvidsson. 
Ardwidsson (1911), p. 11, pi. I, figs. 5-11; pi. II, figs. 39-41. 
R. loveni Willey (1902), p. 276, pi. XLVI, figs. 3-5. 
R. ahtarctica 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 thirteen 
chsetigerons segments, and another portion consisting of six posterior segments, measure 
in all 35 mm. by 1 mm. in diameter. 
*83892—0 
