SYSTEMATIC, 
Gicibe eww SI@AUN DRI 
1. Family CALANIDAE. 
Genus Calanus Leach, 1816. 
In the present report, certain species included in the genus Calanus by Brapy 1883, 
GIESBRECHT 1893, GIESBRECHT & SCHMEIL 1898, SARS 1905 (2), FARRAN 1908, VAN BREEMEN 1908, 
etc., have been removed to other genera on account of structural differences as stated below. 
Calanus finmarchicus (Gunnerus) is regarded as the type of the genus. The antennules 
and mouth organs in both sexes are normal in structure. There are five pairs of bi-ramose feet. 
Each branch is three-jointed and adapted for swimming. The fifth pair of feet in both sexes 
is only very slightly different. In the male, the exopodites of the right and left feet are not 
quite symmetrical. That on the left side is usually a little longer than the right, and it is 
also slightly modified in shape and armature. The anterior surface of the second joint of the 
basiopodite of the first feet in both sexes is furnished with a simple plumose seta. There is no 
hook at the base of this seta, as in the genus Megacalanus. 
Remarks. Under the restrictions adopted in this report, the genus Ca/anus is distinguished 
from the other genera by the almost complete similarity in the structure of the appendages in 
the two sexes. There is no hook-like armature on the anterior surface of the second joint of 
the basiopodite of the first feet. 
Only two species from the ‘Siboga’ collections apparently possessed these characters. 
1. Calanus minor (Claus). 
Cetochilus minor Claus, 1863, p. 172. 
Calanus valgus Brady, 1883, p. 33, pl. Ill, figs. 1—7. 
Calanus valgus 1. C. Thompson, 1888, p. 147. 
Calanus minor Giesbrecht, 1893, p. 90, pl. 6, 7, 8. 
Calanus valgus T. Scott, 1893, p. 24. 
Calanus minor Giesbrecht, 1895, p. 248. 
Calanus minor Giesbrecht & Schmeil, 1898, p. 15. 
Calanus minor Wheeler, 1900, p. 165, figs. a, 0. 
Calanus minor Cleve, 1901, p. 5. 
