20 



Eucalanus crassus is easily identified by its tumid body and very swollen, rounded, 

 genital segment. The body is well covered with short stiff hairs. 



2. Eucalanus monachus Giesbrecht. 



Eucalanus monachus Giesbrecht, 1888, p. 333. 



Eucalanus monachus Giesbrecht, 1893, p. 132, pi. 11 & 35. 



Eucalanus monachus Giesbrecht & Schmeil, 1898, p. 21. 



Eucalanus monachus Wheeler, 1900, p. 167, fig. 4. 



Eucalanus monachus Cleve, 1901, p. 6. 



Eucalanus monachus Thompson & Scott, 1903, p. 242. 



Eucalanus monachus Cleve, 1903, p. 362. 



Eucalanus monachus Cleve, 1904, p. 189. 



Eucalanus monachus Sars, 1905(0), p. 2. 



Eucalanus monachus Wolfenden, 1905 (a), p. 996. 



Eucalanus monachus does not appear to be so widely distributed throughout the oceans 

 as the previous species. It was apparently rather limited in its occurrence in the region traversed 

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



Stat. 19. — Stat. 35. — Stat. ^6. — Stat. 37. — Stat. 47". — Stat. 66. — Stat. 75. — 

 Stat. 93. — Stat. 98. -- Stat. 99. — Stat. 101. — Stat. 110. — Stat. 117". — Stat. 136. — 

 Stat. 138. — Stat. 141. — Stat. 165. - - Stat. 168. — Stat. 169. — Stat. 205. — Stat. 

 215". — Stat. 315. 



This Eucalanus is distinguished from the other species by the broadly rounded and 

 somewhat truncate outline of the head when viewed from the side. 



3. Eucalanus mucronatus Giesbrecht. 



Eucalanus mucronatus Giesbrecht, 1888, p. 333. 



Eucalanus mucronatus Giesbrecht, 1893, p. 132, pis. 11 & 35. 



Eucalanus mucronatus Giesbrecht & Schmeil, 1898, p. 21. 



Eucalanus mucronatus Cleve, 1901, p. 7. 



Eucalanus mucronatus Cleve, 1903, p. 362. 



Eucalanus mucronatus Cleve, 1904, p. 189. 



Eucalanus mucronatus Wolfenden, 1905 (a), p. 996. 



This species was moderately common in the 'Siboga' collections, and appeared to be widely 

 distributed in the area investigated. It was found at the following stations. 



Stat. 36. — Stat. 37. — Stat. 47''. — Stat. 66. — Stat. 75. — Stat. 89. — Stat. 93. — 

 Stat. 96 (night). - - Stat. 98. — Stat. 99. - - Stat. 101. — Stat. 106. — Stat. 110. — 

 Stat. 117'. - - Stat. 118. - - Stat. 121. -- Stat. 124. -- Stat. 125 (day). — Stat. 128. — 

 Stat. 129. - - Stat. 133. • - Stat. 136. — Stat. 138. — Stat. 141. — Stat. 142. — 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. 

 i89 a . — Stat. 194 — 7. -- Stat. 203 (surface). — Stat. 203 (1500 metres). — Stat. 204. — 

 Stat. 2iO\ — Stat. 213. -- Stat. 215*. -- Stat. 216. -- Stat. 217 (horizontal cylinder). — 

 Stat. 220 (vertical net). - - Stat. 220. — Stat. 223. - - Stat. 224. — Stat. 225. - - Stat. 

 230. -- Stat. 243. -- Stat. 245. -- Stat. 252. — Stat. 271. — Stat. 276. — Stat. 282. — 

 Stat. 304. — Stat. 315. 



