I 20 



(surface). — Stat. 220 (Hensen vertical net, 200 metres to surface). — Stat. 230 (HENSEN 

 vertical net, 2000 metres to surface). — Stat. 243 (HENSEN vertical net, 1000 metres to 

 surface). — Stat. 252. -- Stat. 276 (Hensen vertical net, 750 metres to surface). — Stat. 

 282. -- Stat. 304. — Stat. 315. 



The. antennules extend to about the middle of the furcal joints. The anal segment is 

 shorter than the segment immediately in front. The furcal joints are equal to the combined 

 length of the second, third and fourth abdominal segments. 



Lucictitia flavicornis is a comparatively small species. It appears to be widely distributed 

 throughout the great oceans. 



2. Lucicutia claitsi (Giesbrecht). 



Leuckartia clausi Giesbrecht, 1889, p. 812. 



Leuckartia clausi Giesbrecht, 1S93, p. 359, pis. 19 & 38. 



Lucicutia clausi Giesbrecht & Schmeil, 1898, p. III. 



Leuckartia clausi Cleve, 1901, p. 7. 



Lucicutia clausi I. C. Thompson, 1903, p. 26. 



Lucicutia clausi Cleve, 1904, p. 192. 



Lucicutia clausi Sars, i905(/>), p. 3. 



Eight specimens belonging to the above species were obtained from the plankton collected 

 at the following stations. 



Stat. 141 (HENSEN vertical net, 1500 metres to surface), 2 specimens. — Stat. 143 (HENSEN 

 vertical net, 1000 metres to surface), 1 specimen. — Stat. 184, 1 specimen. — Stat. 203 

 (HENSEN vertical net, 1500 metres to surface), 3 specimens. — Stat. 230 (HENSEN vertical 

 net, 2000 metres to surface), 1 specimen. 



Lttcicutia c/ausi is a slightly larger form than Litcicutia flavicornis. The two sexes can 

 easily be distinguished by the presence of a tooth-like projection on each side of the cephalic 

 segment, when the specimen is viewed from above. 



This species appears to be rather rare and its known distribution is limited. 



3. Lucicutia bicornuta Wolfenden. Plate XXXIX, figs. 1 — 11. 



Lucicutia bicornuta Wolfenden, 1905, p. 24, pi. II. 

 Lucicutia aurita G. O. Sars, 1905 (b), p. 8. 

 Lucicutia bicornuta Sars, 1907 («), p. 3. 



A single male specimen identical with the form described and illustrated by Wolfenden 

 in 'Plankton Studies', Part 1, 1905, was found in the plankton collected with the Hensen vertical 

 net at Station 230, 2000 metres to the surface. 



The species is readily recognised by the truncate frontal margin being produced at each 

 corner into a strong spine, and by the presence of a ventrally directed hook-like spine on 

 each side of the cephalic segment. The furcal joints are long and slender. Each furcal joint 

 is as long as the combined length of the whole of the abdominal segments. The rami of the 

 rostrum are very short and stout. The second joint of the basiopodite of the male left fifth 

 foot is produced internally into a short stout process with a dentate apex. Length of 'Siboga' 

 male 8 mm. 



126 



