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Eucalanus mucronatus when in good condition, is easily distinguished from the other 
species of Excalanus by the hook-like projection of the forehead when seen from the side. 
The forehead of the species however, seems to be easily telescoped, and it is therefore not 
always possible to make out the beak at first sight. 
4. Eucalanus prleatus Giesbrecht. 
Eucalanus pileatus Giesbrecht, 1888, p. 334. 
Eucalanus pileatus Giesbrecht, 1893, p. 132, pls. 11 & 35. 
Eucalanus pileatus Giesbrecht & Schmeil, 1898, p. 21. 
Eucalanus pileatus Thompson & Scott, 1903, p. 242. 
Eucalanus pileatus Cleve, 1904, p. 189. 
Eucalanus pileatus Wolfenden, 1905 (a), 996. 
This Aucalanus is apparently not a common species. It was rather scarce in the region 
traversed by the ‘Siboga’ as shewn by the records of its occurrence. 
Stat. 16. — Stat. 19. — Stat. 35. — Stat. 36. — Stat. 37. — Stat. 47°. — Stat. 93. — 
Stat. 96. — Stat. 99. — Stat. 101. — Stat. 106. — Stat. 121. — Stat. 138. — Stat. 165. — 
Stat. 168. — Stat. 169. — Stat. 177%. — Stat. 282. — Stat. 315. 
This species has been recorded from the Red Sea, Atlantic, Pacific, and Indian Oceans 
5. Lucalanus subcrassus Giesbrecht. 
Eucalanus subcrassus Giesbrecht, 1888, p. 334. 
Eucalanus subcrassus Giesbrecht, 1893, p. 132, pls. 11 & 35. 
Eucalanus subcrassus Giesbrecht & Schmeil, 1898, p. 22. 
Eucalanus subcrassus Cleve, 1901, p. 7. 
Eucalanus subcrassus Thompson & Scott, 1903, p. 242. 
Eucalanus subcrassus Cleve, 1903, p. 362. 
Eucalanus subcrassus Cleve, 1904, p. 190. 
Eucalanus subcrassus Wolfenden, 1905(a), p. 996. 
Eucalanus subcrassus although not plentiful, appeared to have a wide distribution in 
the area traversed. It was noted at the following stations. 
Stat. 35. — Stat. 47°. — Stat. 66. — Stat. 81. — Stat. 89. — Stat. 93. — Stat. 96 (day). — 
Stat. 96 (night). — Stat. 98. — Stat. 99. — Stat. 101. — Stat. 106. — Stat. 109. — 
Stat. 112. — Stat. 117°. — Stat. 125 (day). — Stat. 125 (night). — Stat. 129. —. Stat. 
133- — Stat. 136. — Stat. 138. — Stat. 141. — Stat. 144. — Stat. 146. — Stat. 148. — 
Stat. 157 — Stat. 165. — Stat. 168. — Stat. 172. — Stat. 177%. — Stat. 184. — Stat. 185. — 
Stat. 189°. — Stat. 193. — Stats. 1947. — Stat. 203 (surface). — Stat. 203 (1500 metres. — 
Stat. 204. — Stat. 205. — Stat. 217 (horizontal cylinder). — Stat. 220 (vertical net). — 
Stat. 229. — Stat. 252. — Stat. 315. 
This Azcalanus has also been recorded from the Atlantic, Indian, and Pacific Oceans, 
and the Red Sea. 
6. ELucalanus sudtenuts Giesbrecht. 
Eucalanus subtenuzs Giesbrecht, 1888, p. 333. 
Eucalanus subtenuis Giesbrecht, 1893, p. 132, pls. 11 & 35. 
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