So 



i. Phaenna spinifera Claus. 



Phaenna spinifera Claus, 1863, p. 189, pi. XXXI, figs. 1—7. 



Phaenna spinifera Giesbrecht, 1893, p. 293, pis. 5, 12, 37. 



Phaenna spinifera T. Scott, 1893, p. 81, pis. VI & VII. 



Phaenna spinifera Giesbrecht & Schmeil, 1898, p. 50. 



Phaenna spinifera I. C. Thompson, 1903, p. 23. 



Phaenna spinifera Thompson & Scott, 1903, p. 246. 



Phaenna spinifera Cleve, 1903, p. 367. 



Phaenna spinifera Wollenden, 1904, p. m. 



Phaenna spinifera Cleve, 1904, p. 194. 



Phaenna spinifera Sars, 1905 {a), p. 5. 



Phaenna spinifera Wolfenden, 1905^), 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 Cleve. lts presence in various tropical regions has also been made known by other observers. 



Genus XanthocalaniiS 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. Xanthocalanus agilis Giesbrecht. Plate XXXIII, figs. 10 — 18. 



Xanthocalanus agilis Giesbrecht, 1893, p. 286, pis. 12 & 3/. 

 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. 



80 



