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(1902) recorded it from the Farée Channel, but in a later report (1904) withdrew the record, 
stating that all records of the occurrence of this species beyond 30° N. must be looked upon 
with suspicion. The late I. C. THompson (1903) records the species from the collections taken 
during the cruise of the ‘Oceana’ in 1898, at stations in the Atlantic north of 52° N., and 
Professor G. O. Sars (1905) records it from collections taken during the investigations carried 
on by the Prince of Monaco. 
The very strongly projecting forehead, and the structure of the fifth pair of feet in both 
sexes, are the chief points that separate this species from the following one. 
2. Rhincalanus gigas Brady. 
Rhincalanus gigas Brady, 1883, p. 42, pl. VIII, figs. 1—11. 
Rhincalanus gigas 1. C. Thompson, 1888, p. 148. 
Rhincalanus nasutus Giesbrecht, 1888, p. 334. 
Rhincalanus nasutus Giesbrecht, 1893, p. 152, pl. 3, 9, 12, 35. 
Rhincalanus nasutus Canu, 1896, p. 421. 
Rhincalanus nasutus Giesbrecht & Schmeil, 1898, p. 22. 
Rhincalanus gigas 1. C. Thompson, 1900, p. 276. 
Rhincalanus ? gigas T. Scott, 1901, p. 237, pl. XVII, figs. 1—4. 
Rhincalanus ? gigas T. Scott, 1902, p. 450. 
Rhincalanus nasutus Wolfenden, 1902, p. 361. 
Rhincalanus nasutus A. Scott, 1c02, p. 401. 
Rhincalanus grandis Giesbrecht, 1902, p. 8, pl. 1, figs. 15—18. 
Rhincalanus nasutus Sars, 1902, p. 15, pl. VI & VII. 
Rhincalanus nasutus I. C. Thompson, 1903, p. 16. 
Rhincalanus nasutus Thompson & Scott, 1903, p. 242. 
Rhincalanus nasutus Cleve, 1903, p. 368. 
Rhincalanus nasutus Cleve, 1904, p. 196. 
Rhincalanus nasutus Wolfenden, 1904, p. ITI. 
Rhincalanus nasutus Wolfenden, 1905 (a), p. 996. 
Rhincalanus nasutus Sars, 1905 (a), p. 2. 
Rhincalanus nasutus Esterly, 1905, p. 136, fig. 10. 
Rhincalanus nasutus Farran, 1905, p. 30. 
Rhincalanus nasutus Pearson, 1906, p. 8. 
Rhincalanus nasutus Farran, 1908, p. 22. 
Rhincalanus nasutus van Breemen, 1908, p. 18, fig. 14. 
Rhincalanus gigas appeared to be rather a scarce species in the area traversed by the 
‘Siboga’, as shewn by the following records of its occurrence. 
Stat. 118, 2 specimens. — Stat. 125 (night). — Stat. 128, 42 specimen. — Stat. 141. — 
Stat. 142, 6 specimens. — Stat. 165, I specimen. — Stat. 168, 7 specimens. — Stat. 172, 
IO specimens. — Stat. 174, 2 specimens. — Stat. 185, 1 specimen. — Stat. 203 (1500 
metres), 5 specimens. — Stat. 210%, 4 specimens. — Stat. 230. — Stat. 243, 1 specimen. — 
Stat. 276, 6 specimens. — Stat. 282. 
The characters that are adopted to distinguish RAzzcalanus nasutus Giesbrecht, from 
Rhincalanus gigas Brady, are of so little importance that for the present I regard GrEsBRECHT's 
species to be only a small form of RAzucalanus gigas. Brapy’s figures appear to have been 
drawn from imperfect specimens. GirsprecHT himself regarded it as possible, that the form he 
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