lez 
The figure of the fifth pair of feet given by Lussock shews the right and left sides in 
a reversed condition. The endopodite of the true right side is moderately long and curved. It 
has a distinct tooth on the middle of the outer margin. These two points distinguish this fifth 
pair of feet from that of any of the other known males belonging to the genus Scottocalanus. 
The strongly curved endopodite of the right fifth foot, the very short endopodite of the left 
foot along with the dilated inner margin of the second joint of the exopodite, are at once 
obvious on comparing the figure of the Gulf of Guinea specimen, with the illustration given 
in this report. This species differs entirely from Scottocalanus persecans (Giesbrecht), in the 
length of the rostral spines, in the shape of the exopodite of the left fifth foot, and also in 
the shape of the endopodite of the right and left sides. Farran’s suggestion that it is the male 
of Scottocalanus persecans is erroneous, as it differs from that species in the particular points 
already mentioned. 
The absence of a terminal spine on the distal ends of the last thoracic segment shews 
that this form cannot be the male of Scottocalanus setosus, or of Scottocalanus longispinus 
described in the present report. 
Malye (aU SANA NIUR IS VAINIDIRIUA\. 
9g. Family CENTROPAGIDAE. 
Genus Centropages Kroyer, 1848. 
This genus was established by Kroyer in 1848. The forms belonging to it are readily 
recognised by the structure of the fifth pair of feet of the two sexes. The exopodite of the 
female fifth pair of feet is three-jointed. The second joint of the exopodite of the right and 
left sides is produced internally into a strong spiniform process. The shape, length and armature 
of the projection varies in the different species, and forms one of the characters that assist 
in distinguishing them. In the male fifth pair of feet, the left exopodite is composed of two 
joints. The right exopodite is three-jointed. The second and third joints are greatly developed, 
and form a powerful chela. 
Five species were represented in the plankton collected in the Malay Archipelago by 
the ‘Siboga’. 
1. Centropages calantnus (Dana). 
Cyclopsina calanina Dana, 1849, p. 25. 
Centropages calaninus Giesbrecht, 1893, p. 305, pls. 17, 18 & 38. 
Centropages calaninus Giesbrecht & Schmeil, 1898, p. 58. 
Centropages calaninus Cleve, 1901, p. 5. ; 
Centropages calaninus A. Scott, 1902, p. 404. 
Centropages calaninus Thompson & Scott, 1903, p. 247. ° 
Centropages calaninus Wolfenden, 1905(a), p. to14, pl. XCVIII. 
I1I2 
