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Corycaeus gibbulus although not common, appeared to be well distributed in the area 

 investigated by the 'Siboga'. It was present in the plankton collected at the following stations. 



Stat. 35. — Stat. 36. — Stat. 50. -- Stat. 71. — Stat. 75 (Hensen vertical net, 11 metres 

 to surface). -- Stat. 96 (day). — Stat. 96 (night). — Stat. 99. -- Stat. 128 (Hensen vertical 

 net, 700 metres to surface). - - Stat. 142. — Stat. 148 (HENSEN vertical net, 1000 metres 

 to surface). — Stat. 184. — Stat. 186. — Stat. 203 (HENSEN vertical net, 1500 metres to 

 surfacej. — Stat. 213. — Stat. 216. — Stat. 217 (horizontal cylinder). -- Stat. 220 (Hensen 

 vertical net, 200 metres to surface). — Stat. 225. — Stat. 229. — Stat. 276 (Hensen 

 vertical net, 750 metres to surface). — Stat. 304. — Stat. 315. 



The abdomen is composed of two segments. Seen from above, the second segment 

 appears moderately large and funnel-shaped, with the wide end in front. The furcal joints are 

 moderately short and stout. The joints are rather shorter than the anal segment. 



This Corycaeus has been recorded from various parts of the Indian Ocean, and also 

 from the Pacific. 



9. Corycaeus gracilicaudatus Giesbrecht. 



Corycaens gracilicaudatus Giesbrecht, 1891, p. 481. 

 Corycaeus gracilicaudatus Giesbrecht, 1893, p. 661, pi. 51. 

 Corycaeus gracilicaudatus Cleve, 1901, p. 6. 

 Corycaeus gracilicaudatus A. Scott, 1902, p. 421. 

 Corycaeus gracilicaudatus Thompson & Scott, 1903, p. 286. 

 Corycaeus gracilicaudatus Cleve, 1903, p. 361. 

 Corycaeus gracilicaudatus Wolfenden, 1905 (a), p. 1029. 



This species appeared to be rather scarce in the area investigated by the 'Siboga'. It 

 was only observed in the plankton collected at three stations. 



Stat. 142. — Stat. 143 (Hensen vertical net, 1000 metres to surface). — Stat. 304. 



The abdomen of the female is moderately short and rather slender. It is composed 

 of two segments. The genital segment is somewhat inflated in the middle. The second seg- 

 ment is narrow and cylindrical. The furcal joints are comparatively long and slender, and are 

 slightly longer than the anal segment. 



Corycaeus gracilicatidatus has been recorded from various parts of the Indian Ocean 

 and from the Pacific. 



10. Corycaeus longistylis Dana. 



Corycaeus longistylis Dana, 1849, pp. 8 — 61. 

 Corycaeus longistylis Dana, 1852, p. 1212, pi. 85. 

 Corycaeus longistylis Giesbrecht, 1893, p. 661, pi. 51. 

 Corycaeus longistylis I. C. Thompson, 1900, p. 293. 

 Corycaeus longistylis Cleve, 1901, p. 6. 

 Corycaeus longstylis Thompson & Scott, 1903, p. 286. 

 Corycaeus longistylis Wolfenden, 1905^), p. 1026. 



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SIBOGA-EXPEDITIE XXIX a. 



