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1. Phaenna spinifera Claus. 
Phaenna spinifera Claus, 1863, p. 189, pl. XXXI, figs. 1—7. 
Phaenna spinifera Giesbrecht, 1893, p. 293, pls. 5, 12, 37. 
Phaenna spinifera T. Scott, 1893, p. 81, pls. VI & VII. 
Phaenna spinifera Giesbrecht & Schmeil, 1898, p. 50. 
Phaenna spinifera 1. C. Thompson, 1903, p. 23. 
Phaenna spinifera Thompson & Scott, 1903, p. 246. 
Phaenna spinifera Cleve, 1903, p. 367. 
Phaenna spinifera Wolfenden, 1904, p. III. 
Phaenna spinifera Cleve, 1904, p. 194. 
Phaenna spinifera Sars, 1905(@), p. 5. 
Phaenna spinifera Wolfenden, 1905 (a), p. 1009. 
Phaenna spinifera Farran, 1905, p. 43. 
Phaenna spinifera Pearson, 1906, p. 21. 
Phaenna spinifera Farran, 1908, p. 47. 
Phaenna spinifera van Breemen, 1908, p. 56, fig. 63. 
The species appeared to be very scarce in the area investigated by the ‘Siboga’. One 
specimen was obtained from the plankton collected at each of the following stations. 
Stat. 118 (HENSEN vertical net 900 metres to surface). — Stat. 125. — Stat. 143 (HENSEN 
vertical net 1000 metres to surface). — Stat. 144. — Stat. 172. — Stat. 185 (HENSEN 
vertical net 1536 metres to surface). — Stat. 252. — Stat. 276 (HENSEN vertical net 750 
metres to surface). 
Phaenna spinifera has evidently a moderately wide distribution. It has been recorded 
from the deep water off the West of Ireland by Farran, and from off the South African Coast 
by Creve. Its presence in various tropical regions has also been made known by other observers. 
Genus Xanthocalanus Giesbrecht, 1893. 
The females of this genus are separated from Phaenna by the presence of a fifth pair 
of feet. The body is usually more elongated and the last thoracic segment may be pointed. 
The rostrum is bifurcate and the rami are moderately long. The apical lobe of the 
first maxillipedes is furnished with a strong claw-like spine, which is coarsely dentate on the 
inner margin. Cylindrical sensory appendages are also present. The female fifth pair of feet is 
small and three-jointed. In immature females the fifth pair may be only two-jointed. In the 
male, the fifth pair of feet is represented by a long slender left exopodite and a very short 
right exopodite. 
One species was obtained from the plankton collected by the ‘Siboga’. 
1. NXanthocalanus agtlis Giesbrecht. Plate XXXIII, figs. 10—18. 
Xanthocalanus agilis Giesbrecht, 1893, p. 286, pls. 12 & 37. 
Xanthocalanus agilis Giesbrecht & Schmeil, 1898, p. 50. 
One female belonging to this species was found in the plankton collected at each of 
the following three stations. 
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