1912.} R. B. SEyMouR-SEWELL: Surface-Living Copepoda. 337 
Norr.—Since the above was written Grandori (1912) has pub- 
lished a description of a new genus and new species of Copepod 
(Piezocalanus lagunaris). This is very closely related to Paraca- 
lanus and Acrocalanus and it is interesting to note that in this 
form also the mature males present the above characters. 
Family CENTROPAGIDAE. 
Genus Pseudodiaptomus. 
Pseudodiaptomus binghami, sp. nov. 
Pl. xvii, figs. 8—1rr. 
A single specimen of a female was found which, while undoubt- 
edly belonging to this genus, yet presents certain characters 
which indicate that it belongs to a species hitherto undescribed. 
@ Total length 1°3 mm. 
The head was fused with the Ist thoracic segment, and thora- 
cic segments 4 and 5 were also fused together. The posterior 
border of the thorax is rounded and bears a small spine near the 
dorsal surface. Anteriorly the head terminates in a small bifid 
rostrum. 
The abdomen consists of four segments of which the Ist is 
considerably the longest ; their relative proportions together with 
the furcal rami being 45: 25: 30: 12: 28. The ist segment has 
two transverse rows of minute spines on its dorsal surface and 
a row of spines round the dorsal half of its posterior border; 
there is also a small blunt projection on the ventral aspect, 
behind the genital opening. The 2nd and 3rd segments also have 
a row of spines on the dorsal part of the posterior margin. The 
furcal rami are symmetrical and bear 5 short setae, of which the 
third is considerably wider than the others and is spear-shaped. 
‘The 1st antennae unfortunately have their terminal segments 
missing, only 18 being present; the relative lengths of these are 
as follows :— 
Segments— 
I, 2. 3. 4. 5. 6. 7. 8.9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 
IO SON ONOR GSN Ta 1OstI hon buda dae aeons 
The 2nd antennae and mouth parts are of the usual type, 
but the terminal joint of the endopod of the 2nd antenna bears a 
row oi sharp spines. 
The exopodite and endopodite of the Ist—4th pairs of legs 
are 3-jointed and only bear two spines on the external margin 
of the last segment of the exopodite. Thereis no spine on the 2nd 
joint of the exopodite of the rst leg. 
The 5th pair of legs is symmetrical, each consists of three 
segments; the 2nd bears a spine at its outer distal angle and 
the third segment terminates in four spines, three of which are 
short, but the fourth is very long and curved, being longer than 
