sinous in shape, and the distal end is more contracted than in Ccntropagcs gracilis. The right 

 fifth foot of the male is quite distinct from that of the male of Centropages violaceus. 



Wolfenden 1 905(^7) is inclined to doubt the correctness of the record of Centropages 

 vio/accus in 'the report on the Ceylon Copepoda by the late I. C. Thompson and the present 

 writer. He suggests that the species is really Ceiüropages gracilis. Both species however, are 

 recorded in that report from the neighbourhood of Ceylon, in addition to the other records 

 obtained by examining the samples collected during the voyages out to the Island and back. 

 Although Wolfenden did not find Ceiüropages violaceus in the Maldive plankton, it does not 

 follow that it ought to be absent from the Ceylon fauna. Wolfenden's experience amongst the 

 Copepoda ought to have taught him, that it does not always follow that a marine species, 

 no matter where it be originally found, will not prove through some future investigation, to 

 have a wider distribution than its describer could be aware of. The present report gives striking 

 examples of this. Centropages violaceus was described by Claus (not Giesbrecht as Wolfenden 

 has it) from Mediterranean specimens. I have undoubted examples of it from the Atlantic, off 

 Cape Town, obtained from plankton collected by Professor Herdman, during his ocean journeys 

 to and from the meeting of the British Association, in South Africa in 1905. 



Centropages gracilis, so far, is only known from the Indian and Pacific Oceans. 



5. Centropages orsinii Giesbrecht. 



Centropages orsinii Giesbrecht, 1 889, p. 811. 



Centropages orsinii Giesbrecht, 1893, p. 305, pis. 17, iS & 38. 



Centropages orsinii Giesbrecht & Schmeil, 189S, p. 57. 



Centropages orsinii Cleve, 1901, p. 5. 



Centropages orsinii A. Scott, 1902, p. 404. 



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



Centropages orsinii Cleve, 1903, p. 359. 



Centropages orsinii Wolfenden, 1905 (a), p. 1015 pi. XCVIII. 



This member of the genus appeared to be more common than the last species. It had 

 also a slightly wider distribution as shewn by the following records. 



Stat. 16. — Stat. 40. — Stat. 47''. — Stat. 66. — Stat. 71. — Stat. 96 (day). — Stat. 96 

 (night). — Stat. 109. — Stat. 1 10. — Stat. 117". — Stat. 118 (HENSEN vertical net, 900 

 metres to surface). — Stat. 122. — Stat. 133. — Stat. 142. — Stat. 213. — Stat. 282. - 

 Stat. 304. 



Centropages orsinii has a certain amount of resemblance to Centropages kroyeri, but it can 

 readily be separated from that species by the structure of the fifth pair of feet of the two sexes. 

 The projection of the second joint of the exopodite of the female fifth pair is short and stout. 

 It is beset with small spines. In Centropages kroyeri the projection is comparatively slender, and 

 it is without spines. The claw-like joint of the male right fifth foot is longer than the projection 

 of the second joint. In Centropages kroyeri the projection is longer than the claw-like joint. 



Giesbrecht's type specimens where obtained from the Red Sea. The species is evidently 

 well distributed in the Indian Ocean as proved by the later records. 



"5 



