19 
tooth in Undinula darwint, is one-third from the base, and two-thirds from the distal end of 
the spine. 
So far as the records shew, this Calanoid appears to be limited to the Pacific and Indian 
Oceans. Only the males have yet been discovered. 
2. Family EvcaLanipar. 
Genus Eucalanus Dana, 1852. 
The members of this genus are easily distinguished from those belonging to the other 
genera of this family, by the entire absence of a fifth pair of feet in the female. The frontal 
part of the head is not produced into a beak-like prominence. The last abdominal segments 
and furcal joints are not separated. Seven species of Luca/anus were found in the material 
collected by the ‘Siboga’, one of which appears to be undescribed. 
t. Eucalanus crassus Giesbrecht. 
Eucalanus crassus Giesbrecht, 1888, p. 333. 
Eucalanus crassus Giesbrecht, 1893, p. 132, pls. 4, 11, 35. 
Eucalanus crassus Y. Scott, 1897(@), p. 312. 
Eucalanus crassus Giesbrecht & Schmeil, 1898, p. 22. 
Eucalanus crassus Y. Scott, 1900, p. 382. 
UCHIAMUSN CRASSUS) Me SCOtt,, LOOM, Pp. 230. 
Eucalanus crassus Cleve, 1901, p. 6. 
Eucalanus crassus Wolfenden, 1902, p. 361. 
Eucalanus crassus A. Scott, 1902, p. 401. 
NGA ATU GLASSUS MaanSCOLt,, LOOZ, ps 110: 
Eucalanus crassus Thompson & Scott, 1903, p. 242. 
Lucalanus crassus Cleve, 1903, p. 362. 
Eucalanus crassus Cleve, 1904, p. 189. 
Eucalanus crassus Wolfenden, 1904, pp. III, I12. 
Eucalanus crassus Wolfenden, 1905 (a), p. 996. 
Eucalanus crassus Sars, 1905 (a), p. 2. 
Eucalanus crassus Esterly, 1905, p. 134, fig. 8. 
Eucalanus crassus Farran, 1905, p. 30. 
Eucalanus crassus Pearson, 1906, p. 7. 
Eucalanus crassus Farran, 1908, p. 22. 
Eucalanus crassus van Breemen, 1908, p. 16, fig. 13. 
This Ezcalanus, which is apparently widely distributed throughout the oceans as shewn 
by the above references, occurred at the following stations in the area investigated by the ‘Siboga’. 
Siat, 16, —= Sia, o7. = Stat, 66, —= Stave 75. == Sal, So, —= Shiels ©, —— Sais OS. 
Stat, oo — Sta 106, — Stat noo, —= State wiG) — State iat, — siete, 125 (es) 
Stat, 125 (night), — Stet, 138 — Sia iii, == See wie, — Sia Wig. — Sielis Wail. 
Siat. 1aG, —= Sia, m8, — Sta, 168, —— Steve 160, — State, 172, —= Site WAG = Set, FSO). 
Giants, 1O4—=7, <= Sia, aoa, — Sime 206, —= Sieie 220 (Vesicle), — Sie, B52. 
Stat. 282. — Stat. 315. 
1) 
