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body and rounded forehead when seen from the side, and by the rather swollen middle joint 

 of the second pair of maxillipedes. 



Two species were represented in the plankton collected by the 'Siboga' in the Malay 

 Archipelago. 



i. Microsetella norvegica (Boeck). 



Setella norvegica Hoeck, 1864, p. 281. 



Microsetella atlanticum Brady & Robertson, 1873, p. 130, pi. IX, figs. 11 — 16. 



Ectinosoma atlanticum Brady, 1880, vol. II, p. 13, pi. XXXVIII. 



Ectinosoma atlanticum Brady, 1883, p. 100, pi. IV, figs. 10 — 14. 



Microsetella atlantica Giesbrecht, 1893, p. 550, pi. 44. 



Microsetella atlantica T. Scott, 1893, p. 91. 



Microsetella atlantica Giesbrecht, 1S95, p. 261. 



Ectinosoma atlanticum I. C. Thompson, 1896, p. 24. 



Ectinosoma atlanticum T. & A. Scott, 1896, p. 437, pis. 36, 27 & 3^- 



Microsetella atlantica I. C. Thompson, 1900, p. 285. 



Microsetella atlantica Cleve, 1901, p. 7. 



Ectinosoma atlanticum T. Scott, 190 1 (a), p. 352. 



Microsetella atlantica I. C. Thompson, 1903, p. 31. 



Microsetella atlantica Cleve, 1903, p. 364. 



Ectinosoma atlanticum Thompson & Scott, 1903, p. 257. 



Microsetella norvegica Sars, 1904, p. 44, pi. XXIV. 



Ectinosoma atlantica Wolfenden, 1905 (a), p. 1030. 



Ectinosoma atlanticum Pearson, 1905, p. 6. 



Microsetella atlantica Farran, 1905, p. 46. 



Microsetella norvegica T. Scott, 1906(0), p. 309. 



Microsetella norvegica Norman & T. Scott, 1906, p. 137. 



Microsetella norvegica Williams, 1906, p. 652. 



Microsetella norvegica van Breemen, 1908, p. 173, fig. 188. 



Microsetella norvegica Sars, 1909, p. 18. 



This species although very limited in its distribution in the area investigated, was not 



uncommon in one of the collections. It was found at the following stations. 



Stat. 99. — Stat. 217, 277 specimens. — Stat. 271. — Stat. 304. 



The comparatively short furcal setae and the distinctly narrow form of the fifth pair of 

 feet readily separate this species from Microsetella rosea. 



Microsetella norvegica appears to be widely distributed in all the great oceans. 



2. Microsetella rosea (Dana). 



Harpacticus roseus Dana, 1847, p. 153. 



Canthocamptus roseus Dana, 1852, p. 1189, pi. 183, figs. I — 10. 

 Microsetella rosea Giesbrecht, 1893, p. 550, pi. 44. 

 Microsetella rosea I. C. Thompson, 1900, p. 284. 

 Microsetella rosea I. C. Thompson, 1903, p. 32. 

 Ectinosoma roseum Thompson & Scott, 1903, p. 257. 

 Microsetella rosea Cleve, 1903, p. 364. 

 Microsetella rosea Esterly, 1905, p. 211, fig. 52. 

 Microsetella rosea Farran, 1908, p. 91. 

 Microsetella rosea van Breemen, 1908, p. 174, fig. 189. 



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