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Euchaeta concinna, although not very common, appeared to be well distributed throughout 

 the area investigated by the 'Siboga' as shewn by the following records. 



Stat. 16. — Stat. 19. — Stat. 35. — Stat. 36. ■ - Stat. 37. — Stat. 40. — Stat. 66. — 

 Stat. 81. -- Stat. 89. -- Stat. 98. — Stat. 106. -- Stat. 1 10. -- Stat. 117% — Stat. 124. — 

 Stat. 125 (day). — Stat. 128. — Stat. 136. — Stat. 138. — Stat. 141. — Stat. 143. — 

 Stat. 144. — Stat. 146. — Stat. 148. — Stat. 157. — Stat. 165. — Stat. 168. — Stat. 

 169. -- Stat. 172. — Stat. 177'. -- Stat. 184. -- Stat. 185. -- Stat. 186. -- Stat. 189. — 

 Stat. 220 (vertical net). — Stat. 230. — Stat. 243. — Stat. 245. — Stat. 252. — Stat. 

 282. — Stat. 315. 



The female of this species is easily recognised, by the peculiar projection on the proximal 

 end of the right side of the genital segment. The armature on the margin of the second joint 

 of the left exopodite of the male fifth pair is finer than in Euchaeta marina. The onter-edge spine 

 on the second joint of the exopodite of the second pair of feet of the female, is moderately long 

 and stout. It extends nearly to the apex of the first spine on the third joint. The outer-edge 

 spines on the third joint are very short. 



Euchaeta concinna appears to be confined to the tropical seas. 



3. Euchaeta longicornis Giesbrecht. 



Euchaeta longicornis Giesbrecht, 1888, p. 2,2,7. 



Euchaeta longicornis Giesbrecht, 1893, p. 246, pis. 16 & 37. 



Euchaeta longicornis Giesbrecht & Schmeil, [898, p. 40. 



Euchaeta longicornis Cleve, 1901, p. 7. 



Euchaeta longicornis Cleve, 1904, p. 190. 



One female belonging to this species was found in the plankton collected with the 

 Hensen vertical net at Station 141, 1500 metres to surface. 



This species is closely related to Euchaeta marina, and some care is required in its 

 identification. When the antennules are perfect these form a very good character as they extend 

 beyond the furca. 



4. Euchaeta media Giesbrecht. Plate XX, figs. 10 — 18. 



Euchaeta media Giesbrecht, 1888, p. 337. 



Euchaeta media Giesbrecht, 1893, p. 246, pis. 16 & 37. 



Euchaeta media Giesbrecht & Schmeil, 1 898, p. 39. 



Euchaeta media Cleve, 1904, p. 190. 



Euchaeta media Esterly, 1905, p. 160, fig. 25. 



One female belonging to this species was found in the plankton collected with the 

 Hensen vertical net at Station 230, 2000 metres to surface. 



Euchaeta media resembles Euchaeta acuta very closely, but it can be distinguished by 

 the following characters. The left side of the genital segment, when viewed from above, is seen 

 to be considerably swollen. It is broadly rounded in outline, but is not produced into a pointed 

 process. The posterior margin of the last thoracic segment appears distinctly angular, when 

 seen from above, and from the side. The outer-edge spine on the second joint of the exopodite 



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