SERGESTES EDWARDSII. 213 
tapering anteriorly in the largest individuals to a slender acute point, which 
overreaches the anterior margin of the ophthalmic segment. 
The abdominal somites are unarmed, rounded above, the third, fourth, 
and fifth longitudinally suleated on the dorsal face. The telson is sulcated 
on the dorsum and on each side, and ends ina blunt, ciliated point. 
The eye-stalks are shorter than the proximal segment of the antennule; 
the eyes are black, and somewhat greater in diameter than the stalks. The 
first and second segments of the antennule are of about equal length, while 
the third segment is longer than the first or the second by one half. The 
second segment of the antenna of the second pair is armed with a small 
external spine; the scale is lanceolate, terminating in an apical spine; it 
falls short of reaching the distal end of the antennular peduncle. The 
second and third pairs of maxillipeds are robust organs compared with the 
following thoracic appendages; the second pair reach forward as far as the 
distal end of the peduncle of the second antennx ; the third pair are equal 
in length to the whole body, minus the telson and half the sixth somite ; the 
distal part of these appendages is armed with spines of various lengths; four 
of these spines, one of which is terminal, are exceedingly long and acute. 
The following pairs of thoracic appendages have the form characteristic of 
the genus to which this species belongs. 
The petasma of a large male is figured on Plate LL, Fig. 1°. 
The two branches of the last pair of abdominal appendages are longer 
than the telson, the outer branch longer than the inner. The external 
margin of the outer branch is not armed with a spine, but about one third 
of the way from the proximal end this branch of the swimmeret suddenly 
narrows by a change in the trend of the external margin. 
There are six large pleurobranchiz on each side of the body, two on the 
thirteenth, or penultimate thoracic, somite, and one on each of the four ante- 
cedent (ninth to twelfth) somites; a smaller but perfectly formed podo- 
branchia is attached to the base of the second maxilliped. 
Length of one of the largest specimens (Station 3388), 29 mm.; cara- 
pace, 9.3 mm. 
A good many specimens of this pelagic species were taken in the surface 
tow-net and also in the upper, open part of the submarine tow-net at the fol- 
lowing stations: hydr. 2619, hydr. 2627, hydr. 2628, 3382, 3388, 3409, 
3412, 3414. 
Three large males from Station 3388 (one of which is figured on Plate 
