92, AUSTRALASIAN ANTARCTIC EXPEDITION. 
Genus PSEUDOOTHRIX nov. gen. 
(Oothrix Farran, 1905.) 
This proposed new genus differs from Oothrix as described by Farran in having 
swimming feet with bi-articulate exopodites in the absence of “ sausage-shaped sensory 
on the first maxillipedes, and in the bifurcate fifth pair of feet, with rudi- 
2? 
filaments 
mentary exopodite and endopodite. 
PSEUDOOTHRIX ANATINA sp. nov. 
(Plate VII, figs. 1-11.) 
Female (?)—Length 1:55 mm. Anterior antenn jointed, reaching to third 
thoracic segment; rostrum short and thick, duck-bill shaped. Outer branch of the 
posterior antenna slightly longer than the internal. First pair of maxillipeds short and 
stout, with three long distal sete arising from thick, digitiform, much-swollen bases ; 
posterior maxillipeds of the usual type; exopodites of the first pair of feet bi-articulate 
endopodites of one joint only; the second, third, and fourth pairs of feet have both 
endopodites and exopodites bi-articulate, the exopodite much the longer of the two; 
terminal spines as long as the foregoing joint, with finely pectinated outer margin; 
fifth pair of feet very short and stout, each composed of a thick bi-articulate base, from 
which spring two very short subovate digits, representing the exopodite and endopodite. 
Four individuals of this species were observed, one or two of them very deeply pigmented. 
They were taken at Station 11, at a depth of 100 fathoms; one specimen from Station 9. 
These specimens agree in most respects so completely with Farran’s description 
of the genus Oothrix that I am disposed to doubt whether they might not properly be 
referred to that genus. The differences, however, as to the fifth pair of feet are remark- 
able, as also the jointing of the various swimming feet. Moreover, the “ sausage-shaped 
sensory filaments ” of the first maxillipeds, on which Dr. Farran lays special stress, are 
not present in the Antarctic specimens, unless it may be supposed that they are 
represented by the much-dilated bases of the terminal hairs. It is noteworthy that 
Farran’s description rests upon only one undoubted specimen, and it seems not at all 
unlikely that this may have suffered loss of hairs originally attached to the sausage- 
shaped structures. The size of Oothrix bidentata is given as 3 mm., more than twice 
that of the present species. 
Genus PLAGIOPUS nov. gen. 
Anterior antenne having twenty joints, long, slender, and very flexuous. 
Exopodites of the first four feet bi-articulate; endopodites uni-articulate, that of the 
second pair deeply and angularly emarginate, as in the second exopodite of Undina 
vulgaris ; fifth pair simple, each branch composed of a single joint. 
PLAGIOPUS AUSTRALIS: sp. nov. 
(Plate VIII, figs. 1-9.) 
Female.—Length 1:3 mm. Anterior antenne indistinctly jointed at the base, 
terminal joints long and slender, with a distinct bend between the fourteenth and 
