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Pleuromauima xiphias resembles Plcuromamma abdominalis in the strueture of the fifth 

 feet of the two sexes. The males and females, however, can readily be separated by the presence 

 of a prominent spiniform process on the forehead. 



This species appears to have a moderately wide distribution in the great oceans. 



13. Family Lucicutiidae. 



Genus Lucicutia Giesbrecht, 1898. 



The members of this genus can be recognised by the moderately long abdomen, and 

 quite symmetrical furcal joints. The fifth pair of feet of the female is somewhat similar to the 

 third and fourth pairs, but the inner distal angle of the second joint of the exopodite is furnished 

 with an awl-like spine. The exopodite and endopodite of the male left fifth foot are three- 

 jointed. The exopodite and endopodite of the right foot are two-jointed. The right exopodite 

 is claw-like. 



Seven species were represented in the plankton collected during the investigations of 

 the 'Siboga' in the Malay Archipelago. Two of the species appear to be undescribed. 



1 . Lucicutia flavicornis (Claus). 



Leuckartia flavicornis, Claus, 1863, p. 183, pi. XXXII. 



Leuckartia flavicornis, Giesbrecht, 1893, p. 358, pis. 5, 19 & 38. 



Lucicutia flavicornis, Giesbrecht & Schmeil, 1898, p. 111. 



Leuckartia flavicornis, Cleve, 1901, p. 7. 



Leuckartia flavicornis, Wolfenclen, 1902, p. 363. 



Lucicutia flavicornis, A. Scott, 1902, p. 405. 



Lucicutia flavicornis, I. C. Thompson, 1903, p. 25. 



Lucicutia flavicornis Thompson & Scott, 1903, p. 249. 



Lucicutia flavicornis Cleve, 1903, p. 364. 



Lucicutia flavicornis Wolfenden, 1904, p. 11 1 & 112. 



Lucicutia flavicornis Cleve, 1904, p. 192. 



Lucicutia flavicornis Wolfenden, 1905 (a), p. 1012. 



Lucicutia flavicornis Sars, 1905 (b), p. 3. 



Lucicutia flavicornis Farran, 1905, p. 43. 



Lucicutia flavicornis Esterly, 1905, pi 180, fig. $6. 



Lucicutia flavicornis Pearson, 1906, p. 25. 



Lucicutia flavicornis Farran, 190S, p. 64. 



Lucicutia flavicornis van Breemen, 1908, p. 112, fig. 129. 



This species proved to be well distributed in the Malay Archipelago. It was found in 

 the plankton collected at the following stations. 



Stat 16. — Stat. 35. — Stat. $j. — Stat. 47. -- Stat. 66. — Stat. 75 (Hensex vertical 

 net, 11 metres to surface). — Stat. 81. — Stat. 96 (night). — Stat. 98. — Stat. 110. - 

 Stat. u; 1 . — Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 141 (HENSEN 

 vertical net, 1500 metres to surface. — Stat. 143 (HENSEN vertical net, 1000 metres to 

 surface). — Stat. 184. — Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. 

 203 (HENSEN vertical net, 1500 metres to surface). -- Stat. 205. — Stat. 213. — Stat. 220 



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