165 
StdtwlOm se StdtelOu—— “Stat. 35..—— Stat..37: -— Stat. 40... — Stat. ‘so. = Stat. 66, — 
Stat. 75 (HENSEN vertical net, I1 metres to surface). — Stat. 81. — Stat. 93. — Stat. 96 
(day). — Stat. 96 (night). — Stat. 98. — Stat. 99. — Stat. 101. — Stat..106. — Stat. 109. — 
Stat Li2. = Stat. 117", 200) specimens. — Stat. 122: —- Stat: 124, 440 specimens. — 
Stat. 125 (night). — Stat. 136. — Stat. 138. — Stat. 141 (HENSEN vertical net, 1500 
metres to surface). — Stat. 142. — Stat. 144. — Stat. 146. — Stat. 148 (HENSEN vertical 
et OOO Metres sta SULIace))) stats 157, — Stat. 165. —- Stat. 169, — Stat. 172, —— 
Sidtl 7/4 Stat Ze Stata on. —— Stat. 189%. — Stats: 194-7. —- Stat. 208 (sur- 
face) se Std OA Stab eZOh nn Stat. 213..-— Stat. 214) — Stat. 215°) = State 220 
(HENSEN vertical’ net, 200 metres to surface). — Stat. 223. — Stat. 224. — Stat: 225. — 
Stat. 229, — Stat. 245. — Stat. 252. — Stat. 276 (HENSEN vertical net, 750 metres to 
surface). — Stat. 282. — Stat. 304. — Stat. 315. 
Labidocera acuta is readily distinguished by the presence of a median crest on the forehead, 
and by the structure of the fifth pair of feet of both sexes. 
This species appears to have a fairly wide distribution in the warm regions of all the 
great oceans. 
2. Labidocera detruncata (Dana). 
Pontella detruncata Dana, 1849, p. 29. 
Pontellina detruncata Dana, 1852, p. 1143, pl. 80. 
Pontella detruncata Brady, 1883, p. 90, pls. XXVI & XLV. 
Labidocera detruncatum Giesbrecht, 1893, p. 445, pls. 23, 25 & 4I. 
Labidocera detruncata Giesbrecht & Schmeil, 1808, p. 135. 
Labidocera detruncata Thompson & Scott, 1903, p. 251. 
Labidocera detruncata Wolfenden, 1905 (a), p. tor7, pl. XCVIII. 
This Ladézdocera appeared to be rather rare and the distribution was very limited in the 
area investigated by the ‘Siboga’. It was found in the plankton collected at the following 
eight stations. 
Stat. 16, 10 specimens. — Stat. 96 (night), 5 specimens. — Stat. 98, 3 specimens. — Stat. 
110, 20 specimens. — Stat. III, 10 specimens. — Stat. 203 (surface), 7 specimens. — 
Stat. 282, 4 specimens. — Stat. 315, 5 specimens. 
Twenty-four females and forty males were obtained. 
Labidocera detruncata is only known from the Indian and Pacific Oceans. 
3. Labidocera kroyert (Brady). 
Pontella kroyert Brady, 1883, p. 93, pl. XX XIX, figs. 1—19. 
Labidocera kroyert Giesbrecht, 1893, p. 446, pls. 23, 25 & 41. 
Labidocera kroyert Giesbrecht & Schmeil, 1898, p. 135. 
Labidocera kroyere Cleve, 1901, p. 7. 
Labidocera kroyert Thompson & Scott, 1903, p. 251. 
Labidocera kroyert Pearson, 1906, p. 30. 
Labidocera kroyert van Breemen, 1908, p. I51. 
Labidocera kroyert, although represented by fewer specimens, appeared to be more widely 
distributed than Laédzdocera detruncata. Seventeen females and nine males were obtained from 
the plankton collected at the following fourteen stations in the area investigated by the ‘Siboga’. 
165 
