CYCLOPOIDEA. 



1047 



described. When thus abundant, they are food for the right whale, 

 whose arrangement of whalebone in the roof of the mouth serves to 

 strain these minute animals from the water which it ejects by the 

 spout-holes. The species never exceed a quarter of an inch in length, 

 and rarely an eighth of an inch ; as seldom also do they fall short of 

 a twentieth of an inch. 



Subfamily CALANIN^E. 



The Calaninae pass into the Pontellinae through Undina, of the 

 former, which has the posterior prehensile leg in males like Pon- 

 tella, but no geniculating joint in the antennae, and no inferior eyes; 

 and through Hemicalanus and Diaptomus of the latter, which have the 

 geniculating male antenna of Pontella, without the inferior eyes ; and 

 through Acartia, which has the inferior eyes of Pontella, but without 

 probably the geniculating antenna, or prehensile posterior legs. 



The genus Cetochilus of Koussel de Vauzeme,* is essentially iden- 

 tical with Calanus, if the right male antenna is not geniculating, and 

 the inferior eyes are wanting, as would appear from the figures and 

 descriptions. The posterior legs, moreover, are not prehensile, accord- 

 ing to Milne Edwards, who states that he examined sixty specimens. 

 The species C. australis is intermediate between the Calani and 

 Pontellae. The Cetochilus septeiitrionalis of Goodsirf may be the type, 

 however, of a good genus, as recognised on page 1044. This species 

 resembles the females of some Pontellae. 



Genus CALANUS, Leach. 



The species of Calanus are distinguished by having only a single 

 pair of eyes united on a minute spot of pigment ; the anterior feet 

 prolonged and laterally extended, with long unequal setae to each 

 joint ; the posterior legs obsolescent in both sexes ; the antennae alike 

 in both sexes, and neither prehensile. 



* Ann. des Sci. Nat. [2], i. 333, 1834. 



f Jameson's Bdinb. New. Phil. Jour., xxxv. 339, pi. 6, f. 1-11. 





