3i 



Calocalanus pavo Wolfenden, 1905 (a), p. 999. 



Calocalanus pavo Pearson, 1906, p. 9. 



Calocalanus pavo van Breemen, 1908, p. 22, fig. 18. 



Calocalanus pavo although not common, had a moderately wide distribution throughout 

 the area traversed by the 'Siboga' as shewn by the records given. 



Stat. 16. ■ - Stat. 40. - - Stat. 47". — Stat. 50. -- Stat. 75. -- Stat. 96 (day). -- Stat. 96 

 (night). — Stat. 99. — Stat. 101. — Stat. 110. — Stat. 118. — Stat. 121. —Stat. 133. — 

 Stat. 138. -- Stat. 141. — Stat. 148. — Stat. 203 (1500 metres to surface). — Stat. 213. - 

 Stat. 215". - - Stat. 217 (horizontal cylinder). - - Stat. 220 (vertical net). — Stat. 224. — 

 Stat. 229. -- Stat. 243. — Stat. 271. -- Stat. 276. — Stat. 282. — Stat. 304. 



This species is easily identified by its two-jointed abdomen, and by the peculiar position 

 of the furcal joints. The furcal joints are symmetrical and are nearly always spread at right 

 angles to the abdomen. None of the specimens had the caudal setae in the perfect condition 

 so well shewn by Giesbrecht. 



Calocalanus pavo has a wide distribution in the warm seas, and it has been frequently 

 recorded from various parts of the great oceans. 



2. Calocalanus plumulosus (Claus). 



Calanus plumulosus Claus, 1863, p. 174, pi. XXVI, figs. 15 & 16. 



Calocalanus plumulosus Giesbrecht, 1893, p. 176, pis. 3, 9, 36. 



Calocalanus plumulosus T. Scott, 1893, p. 39, pis. 1 & 6. 



Calocalanus plumulosus Giesbrecht & Schmeil, 1898, p. 26. 



Calocalanus plumulosus Wheeler, 1900, p. 170, fig. 8. 



Calocalanus plumulosus A. Scott, 1902, p. 403. 



Calocalanus plumulosus Thompson & Scott, 1903, p. 243. 



Calocalanus plumulosus Wolfenden, 1905 (a), p. 999. 



This Calocalanus appeared to be rather a rare species in the area investigated, and 

 was only observed in the plankton collected at the following eleven stations. 



Stat. 33. — Stat. 47''. — Stat. 75. — Stat. 121. — Stat. 146. — Stat. 148. — Stat. 184. - 

 Stat. 217 (horizontal cylinder). — Stat. 271. — Stat. 282. — Stat. 304. 



Calocalanus plumulosus is easily separated from Calocalanus pavo, by its three-jointed 

 abdomen and asymmetrical furca. The left furcal joint is larger than the right, and it is not 

 separated from the anal segment. The left furcal joint is furnished with a very long plumose 

 seta, but this is seldom perfect in specimens taken in ordinary tow-net collections. 



This species has a distribution somewhat similar to the previous one. 



4. Family Pseudocalanidae. 



Genus Clausocalanus Giesbrecht, 1888. 



This genus is distinguished from the other members of the family chiefly by the structure 

 of the fifth pair of feet of both sexes. The fifth pair is symmetrical in the female and has 



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