243 
Stat. 143 (HENSEN vertical net, 1000 metres to surface), 2 specimens. — Stat. 148 (HENSEN 
vertical net, 1000 metres to surface), 2 specimens. 
Oncaea tenuimana can be recognised by the rather long abdomen and comparatively 
short furcal joints. 
This species is evidently rather limited in its distribution. It does not appear to have 
been recorded by any other observer since GirsprecuT described it from specimens found in 
plankton collected in the Pacific Ocean. 
5. Oncaea venusta Philippi. 
Oncaea venusta Philippi, 1843, p. 62, pl. 4. 
Oncaea venusta Giesbrecht, 1893, p. 590, pls. 2, 3 & 47. 
Oncaea venusta 1. C. Thompson, 1900, p. 286. 
Oncaea venusta Wheeler, 1900, p. 190, fig. 27. 
Oncaea venusta A. Scott, 1902, p. 418. 
Oncaea venusta Thompson & Scott, 1903, p. 284. 
Oncaea venusta Cleve, 1903, p. 366. 
Oncaea venusta Cleve, 1904, p. 194. 
Oncaea venusta Wolfenden, 1905(a), p. 1020. 
Oncaea venusta Pearson, 1906, p. 34. 
Oncaea venusta Norman & T. Scott, 1906, p. 197. 
Oncaea venusta van Breemen, 1908, p. 186, fig. 1098. 
This proved to be 
the most common and widely distributed member of the genus in the 
area investigated by the ‘Siboga’. It was present in the plankton collected at the following stations. 
Stat 16. — Stat. 35. — Stat. 36. Stat. 37. — Stat. 4o. Stat. 47°. — Stat. 50. — Stat. 66, — 
Stat. 71. — Stat. 75 (HENSEN vertical net, 11 metres to surface). — Stat. 81. — Stat. 89. — 
Stat. 93. — Stat. 96 (day). — Stat. 98. — Stat. 99. — Stat. 101. — Stat. 110. — Stat. 112. — 
Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 121. — Stat. 122. — Stat. 
125 (day). — Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 133. — Stat. 136. — 
Stat. 138. — Stat. 141 (HENSEN vertical net, 1500 metres to surface). — Stat 142. — Stat. 143 
(HENSEN vertical net, 1000 metres to surface). — Stat. 144. — Stat. 148 (HENSEN vertical 
net, 1000 metres to surface). — Stat. 157. — Stat. 165. — Stat. 168. — Stat. 169. — Stat. 
184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. 186. — Stat. 193. — 
Stat. 194—7. — Stat. 203 (surface). — Stat. 203 (HENSEN vertical net, 1500 metres to 
surface). — Stat. 205. — Stat. 210°. — Stat. 213. — Stat. 216. — Stat. 217 (horizontal 
cylinder). — Stat. 220 (surface). — Stat. 220 (HENSEN vertical net, 200 metres to surface. — 
Stat. 223. — Stat. 224. — Stat. 229. — Stat. 243 (HENSEN vertical net, 1000 metres to 
surface. — Stat. 252. — Stat. 271. — Stat. 276 (HENSEN vertical net, 750 metres to sur- 
face. — Stat. 282. — Stat. 304. — Stat. 315. 
Oncaca venusta can readily be separated from the other members of the genus by the 
comparatively long furcal joints. The furcal joints are longer than the combined length of the 
third and fourth abdominal segments. 
This species is widely distributed in the warm regions of all the great oceans. 
Genus Conaea Giesbrecht, 1891. 
This genus is closely related to Oxcaea, but it is readily separated by the long end 
joint of the antennae with its armature of very long and slender curved spines. 
One species was represented in the plankton collected by the ‘Siboga’. 
243 
