NEMATOBRACHION FLEXIPES. 271 
second segments a little angular or conspicuously angular above in the middle 
line (fig. 5g). The lateral plates of second to fifth segments with the postero- 
lateral angle acute, and the plate of fifth segment besides somewhat produced 
(fig. 5g). Preanal spine simple in the male and with an accessory tooth in the 
female.— Uropods about as long as the telson; the exopod slightly or scarcely 
longer than the endopod.— The telson with two pairs of small dorsal spines. 
The copulatory organs (figs. 5h—5m) differ from those in N. boopis by the 
shape of the terminal and the proximal processes. The terminal process is 
somewhat less thickened at the base, tapering to the narrow middle and then 
flattened and almost abruptly and strongly expanded on the outer side and 
feebly expanded on the inner side; the distal half is, seen from behind (fig. 5i), 
shaped nearly as an oblique triangle with the inner margin somewhat sinuate, 
the outer proximal angle very broadly rounded and the vertex narrowly rounded; 
a little from the distal end the posterior side shows a peculiarly raised part, the 
shape of which is better understood when looked at from the outer side (p’. 
on fig. 5k). The proximal process is somewhat broader than in N..boopis and 
more evenly curved, its distal half is somewhat depressed, and thus broader 
than deep; the terminal part is much flattened and considerably expanded, 
forming, seen from the base of the organ, an oblong-oval plate (fig. 5m) with 
nearly the whole margin finely serrate. The median lobe long and slender 
(fig. 5h) with its two processes nearly as in NV. boopis; the two remaining lobes 
nearly as in that species. 
Length of a large male 21.5 mm., of a female 22.5 mm. 
Remarks.— N. flexipes differs in general aspect much from WN. boopis, 
but it would be a mistake to establish a new genus for its reception, because both 
species agree with each other in all characters of real generic value. It may 
be mentioned here that even in less than half-grown specimens the carapace 
has no vestige of any tooth on the lateral margins. 
Distribution— This species was established on two specimens from the 
Southern equatorial current in the Atlantic. The Copenhagen Museum possesses 
D>, 
16’ W., and Lat. 24° 3’ N., long. 25° 0’ W. It is unknown from the Indian 
Ocean and the Western Pacific, but according to the long list of Stations it is 
common in the major part of the area explored in 1904-5 in the East Pacific, 
viz. between Lat. 9° 45’ N., and Lat. 25° 27’ S. Ortmann has recorded it from 
two Stations in the same area, viz. off Panama at Lat. 6° 21’ N., and at Lat. 
0° 36’ N., long. 82° 45’ W. The specimens in the Copenhagen Museum were 
