224 STALK-EYED CRUSTACEA. 
a strong lens; on the following pairs of limbs this little vestige of the outer 
branch becomes somewhat larger (see Plate LIV., Fig. 1"), but still remains 
a mere rudiment of the part as developed in P. armiger. 
Length, 31 mm. 
Station 2637 Hydr. 700 fathoms (tow-net). 1 male. 
The sounding at Station 2657 is 773 fathoms. The Tanner net was 
towed at 700 fathoms for twenty minutes, but it came up open all the way 
to the surface. 
SCOLOPHTHALMUS Fax. 
Bull. Mus. Comp. Zoél., XXIV. 219, 1893. 
Integument membranaceous.. Carapace small, leaving the last two tho- 
racic segments exposed; produced in front to a spiniform rostrum, and 
armed with a pair of antennal, and a pair of branchiostegal spines; cervical 
sulcus distinct, with a linguiform dorsal area behind it. Abdomen slender, 
subcylindrical, sixth segment the longest. Telson broad, apex truncate, not 
incised. Hye-stalks transformed to sharp spines, visual elements absent. 
Peduncle of first pair of antennz robust, long, much exceeding the peduncle 
of the second pair of antennz, and reaching nearly as far forward as the tip of 
the scale of the second antennz; the three segments subequal. Peduncle 
of the second pair of antenne rather short and slender; scale much longer 
than the peduncle, narrow, tapering at the distal end, proximal fourth of 
outer border smooth, naked, terminating in an angle which bears a strong 
spine-like seta; the rest of the outer border of the scale is fringed with hair- 
like sete like the inner border. Mandibular palp stout, long, reaching be- 
yond the middle of the peduncle of the first pair of antenne; first segment 
short, second segment very long, third segment narrowly oblong, one half as 
long as the second segment. Second maxille with inner basal part ex- 
panded, three lobed, terminal segment expanded at the distal end, trian- 
gular; scaphognath rather small. Maxillipeds short, broad, third segment 
very short, fourth, fifth, and sixth segments about equal in length, seventh 
segment small and armed at the tip with one or two strong stiff sete; the 
inner borders of the three antecedent segments also bear a few setae; the 
sixth (penultimate) seement is broad and triangular; there is no porrect 
internal lobe to the maxilliped, such as found in some of the allied genera ; 
neither is there any exopod, but the basal segment bears a long, well devel- 
oped epipod. The first pair of legs (gnathopods) are of moderate length ; 
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