IO 



Genus Calanoides Brady, 1883. 



This genus was established by Brady in the 'Challenger' report, for the reception of a 

 Calanoid form whose male possessed characters quite distinct from those of Calanus, the most 

 important being the prehensile structure of the fifth feet. The exopodites of this pair are three- 

 jointed, elongated, and destitute of plumose setae. The endopodites are rudimentary. That of 

 the right foot is three-jointed. The left one is reduced to a single small joint. The absence of 

 plumose setae on the male fifth feet indicate, that they are not adapted for swimming, and thus 

 differ from those of typical Calanus. The female is of the usual Ca/anus type. Giesbrecht in 

 his great work 'Fauna und Flora des Golfes von Neapel' and Giesbrecht & Schmeil in 'Das 

 Tierreich', include this genus under Calanus. The fifth feet of the male however, are so obviously 

 distinct, that its position there is untenable, and it must therefore be restored as a separate 

 genus. The presence of a normal fifth pair of feet in the female, indicates that the genus is 

 related to Calanus, and not to Pseudocalanus or Euchaeta, as suggested by Brady. 



No specimens of Calanoides patagonicnsis Brady, the type of the genus, were found in 

 the 'Siboga' collections, but there is so close a resemblance in the structure of the male fifth 

 feet of Calanus brevicornis Lubbock, to Calanoides, that it has been included under that genus 

 in this report. The genus is now represented by two species, one of which occurred in the 

 plankton collected by the 'Siboga'. 



1 . Cala7ioides brevicornis (Lubbock). 



Calanus brevicornis Lubbock, 1856, p. II, pi. III. 



Calanus brevicornis Giesbrecht, 1893, p. go, pi. 6, 7, 8. 



Calanus frontalis Dahl, 1894, p. j6. 



Calanus brevicornis Giesbrecht & Schmeil, 1S98, p. 16. 



Calanus brevicornis Cleve, 1904, p. 185. 



Calanus brevicornis Sars, 1907 (b), p. 4. 



This species is easily recognised by its conical and slightly crested forehead, and by the 

 rather pointed terminations of the last thoracic segment. The female is of the normal Calanus 

 type. The fifth pair of feet of the male although not so elongated as in Calanoides palagoniensis, 

 is of a somewhat similar structure to that of Brady's species. The endopodites of both rami 

 are rudimentary, that of the right side is three-jointed. The left is reduced to one small joint. 

 It was noted in collections taken at the followinaf stations. 



Stat. 165, 20 specimens. — Stat. 168. — Stat. 169, 1 specimen. — Stat. 172, 2 specimens. — 

 Stat. 185. — Stat. 225, 1 specimen. — Stat. 230, 5 specimens. — • Stat. 276, 3 specimens. 



Calanoides brevicornis (Lubbock), has previously been recorded from the Atlantic and 

 Indian Oceans only. 



Genus MegacalaiTUS Wolfenden, 1904. 



Wolfenden 1904 (wrongly quoted as 1905 in Plankton Studies, part I) briefly described a 

 very large Calanoid form under the abovè genus that, was taken in the deep water of the Atlantic, 



