i 14 



Centropages furcatus Cleve, 1901, p. 5. 

 Centropages furcatus A. Scott, 1902, p. 403. 

 Centropages furcatus Thompson & Scott, 1903, p. 246. 

 Centropages furcatus Cleve, 1903, p. 359. 

 Centropages furcatus Cleve, 1904, p. 187. 

 Centropages furcatus Wolfenden, 1905 (a), p. 1016. 



This was by far, the most common and widely distributed member of the genus represented 

 in the plankton collected by the 'Siboga' as the following records shew. 



Stat. 16. — Stat. 35. — Stat. 37. — Stat. 47". — Stat. 50. — Stat. 66. — Stat. 71. — 

 Stat. 81. — Stat. 89. • - Stat. 93. — Stat. 96 (day). — Stat. 96 (night). — Stat. 98. — 

 Stat. 99. — Stat. 101. — Stat. 106. — Stat. 109. — Stat. 117". — Stat. 125 (day). — 

 Stat. 128 (Hensen vertical net, 700 metres to surface). — Stat. 136. — Stat. 141 (Hensen 

 vertical net, 1500 metres to surface). — Stat. 142. — Stat. 143 (HENSEN vertical net, 

 1000 metres to surface). — Stat. 146. — ■ Stat. 148 (HENSEN vertical net, 1000 metres to 

 surface). — Stat. 165. — Stat. 169. — Stat. 174. — Stat. 184. — Stat. 185 (HENSEN 

 vertical net, 1536 metres to surface). — Stat. 203 (HENSEN vertical net, 1500 metres to 

 surface). — Stat. 204. — Stat. 205. — Stat. 213. — Stat. 214. — Stat. 217 (horizontal 

 cylinder). — Stat. 220 (HENSEN vertical net, 200 metres to surface). — Stat. 224. — 

 Stat. 245. — Stat. 282. — Stat. 304. — Stat. 315. 



Centropages furcatus can readily be recognised by its slender body, by the spiniform 

 prolongations of the last thoracic segment, and by the very short middle segment of the abdomen 

 of the female. The structure of the fifth pair of feet of both sexes is also characteristic. 



This species has apparently a moderately wide distribution in -the tropical seas. 



4. Centropages gracilis (Dana). 



Cyclopsina gracilis Dana, 1849, p. 25. 



Centropages gracilis Giesbrecht, 1893, p. 305, pis. 17 & 38. 



Centropages gracilis Giesbrecht & Schmeil, 1898, p. 57. 



Centropages gracilis Cleve, 1901, p. 5. 



Centropages gracilis Thompson & Scott, 1903, p. 247. 



Centropages gracilis Cleve, 1903, p. 359. 



Centropages gracilis Wolfenden, 1905 [o], p. 1013, pi. XCVIII. 



This Centropages was not uncommon in the plankton obtained during the investigations 

 in the Malay Archipelago. The distribution was comparatively wide. Examples of it were found 

 at the following stations. 



Stat. 37. — Stat. 66. — Stat. 81. — Stat. 93. — Stat. 96 (day). — Stat. 96 (night). — 

 Stat. 98. - - Stat. 118 (Hensen vertical net, 900 metres to surface). — Stat. 13S. — Stat. 

 203 (Hensen vertical net, 1500 metres to surface). ■ — Stat. 217 (horizontal cylinder). — 

 Stat. 276 (HENSEN vertical net, 750 metres to surface). — Stat. 282. 



Centropages gracilis resembles Centropages violaceus in general appearance. The females 

 however, can easily be distinguished by the distinct knob-like projection on the lateral margins 

 of the second abdominal segment when seen from above. The surface of each knob is covered 

 with fine short spines. The fifth pair of feet of both sexes is also distinct. The projection of 

 the second joint of the exopodite of the female fifth pair is nearly straight. It is moderately 

 stout and is almost as long as the third joint. In Centropages violaceus the projection is somewhat 



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