42 
R. NORRIS WOLFENDEN. 
Posterior foot jaws with segments proportionately Bl, B 2, Ri — 9, 8, 9. Ri 
elongated and thin, with five distinct segments. 
First feet, Ri of one, Re of three segments, the first without Se ; Ri with four Si. 
Second feet, Ri of two, Re of three segments ; no Si on B I or B 2. 
Fourth feet, Ri and Re of three segments each. The end saw extremely long, and 
longer than the whole Re, broad and coarsely serrated marginally. 
In the second to the fourth feet the Re 3 has three outer marginal spines. No 
fifth feet. 
The few males present were apparently immature. 
IIALOPTILUS (Giesbrecht). 
One species of this genus appears to be characteristic of the Antarctic fauna, since 
it is present in very many of the ‘ Gauss ’ samples, but curiously enough, occurred only 
once in the ‘ Discovery ’ collection. It is large, and distinguished at a glance from any 
other examples of the genus by the prominent black ocellus clorsally placed, an organ 
not possessed by any other species of Haloptihis. 
Haloptilus ocellatus. 
(Plate IIP, figs. 1, 2.) 
Haloptilus ocellatus, Wolfenden, Plankton Studies, Part I. (1905), p. 14. 
?, of length, from the end of the frontal spine to the end of the furca, 875 mm., 
with cephalothorax over five times as long as the abdomen; the conjoined head and 
first segment much longer than the remaining segments of the anterior body (about 
one-third) ; the last two segments of the cephalothorax united, and with rounded 
margins. On the second segment, in the centre of the dorsum, or a little to the right 
of the centre, is a prominent and very black rounded pigmented ocellus, standing out 
in clear contrast to the rest of the very transparent animal. The frontal spine is long, 
tapering, and usually a little curved downward, and often laterally, towards the tip. 
The distance from the tip of the spine to the base of the anterior antennse is equal to 
the distance between the latter and nearly to the distal end of the second cephalic 
segment. Abdomen of four segments, with the anal as long as the two preceding, and 
the furcal segments over twice as long as broad. 
Anterior antennte a little longer than the whole animal, reaching beyond the furca 
by about three or four joints, and sparingly setiferous. 
Posterior antennse with endopodite very long and exopodite very short, the latter 
of six joints, with doubtful division of the last, which would be the seventh joint, the 
basal or first segment very long, and nearly as long as the joints distal to it. Re not 
