1912.| R. B. SEyMOuUR-SEWELL : Surface-Living Copepoda. 363 
4. Centropages tenuiremis, Thompson and Scott. 
Pl. xxiv, figs. 6—7. 
C. tenutremis, Thompson and Scott, Report on the Cope- 
poda. Ceylon Pearl Oyster Fisheries and Marine Biology, 
(Suppl. Rept. vii), vol. 1, p. 247, pl. i, figs. rg—18, 1903. 
C. arabicus, Cleve, Report on Plankton collected by Mr. 
Thorild Wulff during a voyage to and from Bombay, 
Arkiv for Zoologi, vol. i, p. 371, pl. 16, figs. r—9; pl. 17, 
fig. I, 1903-4. 
Occurrence: Localities C and E. 
Numerous specimens were obtained in the above localities 
and agree very well with the descriptions of Cleve, and Thompson 
and Scott. The latter, however, state that in their examples the 
abdomen of the female possesses four segments (they only figure it 
with three). As Cleve (loc. cit.) points out, the rst and 2nd segments 
of the exopod of the right 5th leg of the female are fused to- 
gether, a point apparently overlooked by Thompson and Scott. 
Both authors figure the spine as arising from the Ist segment. I 
have examined a large number of specimens, but can find no 
evidence whatever in favour of this view; on the contrary, where 
any trace of separation can be made out, it invariably runs on 
the proximal side of the spine, which therefore arises, as one 
would have expected, from the distal portion of the fused segment 
(vide pl. xxiv, fig. 6). A second point in which my examples ap- 
pear to differ is in the length of the endopodite which reaches to the 
end of the spine, whereas both the previous authors show it as 
falling considerably short of this. Possibly this latter is a local 
variation, as Cleve figures it much shorter in his examples than in 
those from Ceylon. 
Another point in which my specimens differ is in the 4th 
pair of legs of the male. Thompson and Scott state that in their 
specimens this appendage resembled that of C. typicus, that is to 
say the marginal spine of the 2nd joint of the exopodite of the 
3rd and 4th legs of the right side is increased in length in com- 
parison with its fellow of the opposite side. In all the specimens 
that I have examined, however, the 3rd pair of legs is sym- 
metrical and the 4th leg of the right side bears enlarged spines on 
both exopod 1 and 2. 
Genus Pseudodiaptomus, Herrick. 
1. Pseudodiaptomus aurivillii, Cleve. 
A few specimens were obtained in locality Q; they were, 
without exception, females and agreed with Cleve’s description. 
