• i88 



The female can readily be recognised by the long naked claw-like spine on the fifth 



pair of feet. 



This species was first recorded from the Red Sea, but it has since been obtained from 



various parts of the Indian Ocean. 



3. Acartia negligens Dana. 



Acartia negligens Dana, 1849, p. 26. 



Acartia negligens Giesbrecht, 1S93, p. 508, pis. 30 & 43. 



Acartia negligens Giesbrecht & Schmeil, 1898, p. 154. 



Acartia negligens Cleve, 1901, p. 4. 



Acartia negligens A. Scott, 1902, p. 408. 



Acartia negligens Thompson & Scott, 1903, p. 254. 



Acartia negligens Cleve, 1903, p. 355. 



Acartia negligens Wolfenden, 1905(0), p. 1023, 



Acartia negligens Sars, 1907(0), p. 27. 



The spine on the fifth pair of feet of the female of this species is somewhat similar to 

 that on the fifth pair of Acartia danae. The two forms can readily be separated, however, by 

 the form of the last thoracic segment. In the present species the posterior margins of the last 

 thoracic segment are rounded and the distal ends are each furnished with a very small spine. 

 The last thoracic segment of Acartia danac is produced on each side into a strong spine. 



Acartia negligens appeared to have a fairly wide distribution in the area traversed by 

 the 'Siboga'. It was found at the following stations. 



Stat. 36. — Stat. 40. — Stat. 47''. — Stat. 71. — Stat. 96 (day). — Stat. 110. — Stat. 125 (day). — 

 Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 133. — Stat. 138. — 

 Stat. 141 (HENSEN vertical net, 1500 metres to surface). — Stat. 142. — Stat. 148 (Hensen 

 vertical net, 1000 metres to surface). — Stat. 165. — Stat. 168. — Stat. 174. — Stat. 185 

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

 metres to surface). — Stat. 205. — Stat. 213. — Stat. 217 (horizontal cylinder). — Stat. 

 Stat. 245. — Stat. 252. — Stat. 276 (HENSEN vertical net, 750 metres to surface). ■ 

 Stat. 282. — Stat. 304. 



This Acartia has been recorded from the Mediterranean, Arabian and Red Seas, Indian 

 and Pacific Oceans, and from the Malay Archipelago. 



4. Acartia sfiinicattda Giesbrecht. 



Acartia spinicauda Giesbrecht, 1889, p. 25. 



Acartia spinicauda Giesbrecht, 1893, p. 508, pis. 30 & 43. 



Acartia spinicauda Giesbrecht & Schmeil, 1898, p. 155. 



Acartia spinicauda Cleve, 1901, p. 4. 



Acartia spinicauda Cleve, 1903, p. 355. 



This Acartia resembles Acartia centrura in general appearance, but it can readily be 

 separated by the form of the spine on the fifth pair of feet of the female. The spine is long 

 and slender. It appears to be articulated to a short stout basal part attached to the end of 

 the free joint. 



