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Genus Phyllopus Brady, 1883. 



The members of this genus are readily recognised by the structure of the fifth pair of 

 feet of the two sexes. The female fifth pair has a two-jointed basiopodite, and a three-jointed 

 exopodite. There is no tracé of an endopodite on either foot. The terminal joint of the exopodite 

 is leaf-like. The apex is rather deeply and irregularly serrate. The male fifth pair is well 

 developed and prehensile. The exopodite of each foot is two-jointed. The left foot only is 

 furnished with a rudimentary lamelliform endopodite. 



The genus was established by Brady in 1883 from a single specimen that was undoubtedly 

 a female. Wolfenden's statement, in the Journal of the Marine Biological Association, April 

 1904, page 124, that it was a male is a curious error as he describes the male in the same 

 report. The late I. C. Thompson appears to have been the first observer to give an account 

 of the male, but he wrongly identifies his species with the type of the genus. Thompson, 

 Wolfenden and Esterly state that the right foot has a rudimentary endopodite. This is an 

 error due to an imperfect preparation or a reversal of the right and left sides. Esterly, however, 

 only found one female and his description of the male was taken from Wolfenden's report. 



There appears to be some confusion regarding the type species. Other forms have been 

 recorded by some writers as Phyllopus bidentatus that are clearly distinct. Farran (1908) has 

 done much to clear up the difficulty, and has established two additional species. 



Four species belonging to this genus were obtained from the plankton collected by the 

 'Siboga' in the Malay Archipelago. 



1. Phyllopus bidentatus Brady. Plate XLV, figs. 1 — 9. 



Phyllopus bidentatus Brady, 1883, p. 78, pi. V, figs. 7 — 16. 

 Phyllopus bidentatus T. Scott, 1893, p. 74, pi. VI, fig. 26. 

 Phyllopus bidentatus Sars, 1905 (b), p. 5. 



Eight males and three females apparently identical with Brady*s type species- were found 

 in the plankton collected at the following stations. 



Stat. 118 (HENSEN vertical net, 900 metres to surface), 1 male. -- Stat. 128 (HENSEN vertical 

 net, 700 metres to surface), 1 male, 1 female. — Stat. 141 (HENSEN vertical net, 1500 

 metres to surface), 1 male, 1 female. — Stat. 185 (HENSEN vertical net, 1536 metres to 

 surface), 2 males. — Stat. 203 (HENSEN vertical net, 1500 metres to surface), 1 male. — 

 Stat. 2 [6, 1 male. — Stat. 276 (HENSEN vertical net, 750 metres to surface), 1 male and 

 1 female. 



The females although resembling Brady's type in the prolongation of the last thoracic 

 segment, differ from it by the projection being obliquely truncate at the apex, when seen from 

 the side, instead of distinctly forked as shewn by that author. The terminations of the last 

 thoracic segment are asymmetrical, both in length and in shape. The left side extends to the 

 middle of the genital segment. The apex is pointed (Plate XLY, fig. 3). The right side extends 

 to near the distal end of the genital segment. The apex is obliquely truncate, with a very 

 minute point at each extremity (Plate XLV, fig. 4). 



The combined length of the abdomen and furca is equal to slightly more than one 



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