SYSTEMATIC. 



Tribe AMPHASKANDRIA. 

 i. Family Calanidae. 



Genus Calanus Leach, 1S16. 

 In the present report, certain species included in the genus Calanus by Brady 1883, 



GtESBRECHT I 893, GlESBRECHT & ScHMEIL 1898, SaRS 1905(0:), F.\RRAN 1908, VAN BREÉMEN I guS, 



etc, have been removed to other genera on account of structural differences as stated below. 



Calanus fiumarchicus (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 ancl 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 turnished 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 Calanus 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 l Siboga' collections apparently possessed these characters. 



1 . Calanus minor (Claus). 



Cetochilus minor Claus, 1863, p. 172. 



Calanus valgus Brady, 1883, p. 33, pi. III, figs. 1 — 7. 



Calanus valgus I. C. Thompson, 1888, p. 147. 



Calanus minor Giesbrecht, 1893, p. 90, pi. 6, 7, 8. 



Calanus valgus T. Scott, 1893, p. 24. 



Calanus minor Giesbrecht, 1895, p. 248. 



Calanus minor Giesbrecht & Schmeil, 1S98, p. 15. 



Calanus minor Wheeler, 1900, p. 165, figs. a, b. 



Calanus minor Cleve, 1901, p. 5. 



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