DIOSACOUS. 69 
LX, fig. 14). Anterior antenne slender ; in the female 
the first four joints are unitedly three times as long 
as the following four, and somewhat sparingly setose. 
Posterior antenne (Pl. LIX, fig. 13) large, 2-jointed, 
the joints slender and nearly equal; a small 1-jointed 
secondary branch springing from the middle of the 
first joint. Mandible (fig. 14) short and stout, palp 
short, 2-jointed. The hand of the second foot-jaw (PI. 
LX, fig. 16) is pear-shaped, swollen towards the base, 
and fringed along the middle of the inner margin with 
a number of short cilia; terminal claw 2-jointed and 
much curved. Outer branch of the first foot (fig. 17) 
half the length of the first joint of the inner branch. 
Inner branch of the second foot of the male (Pl. LIX, 
fic. 15) short, 2-jointed, the third jot giving place to 
two spines and a long seta. Tifth pair of feet 2- 
jointed; in the female (Pl. LX, fig. 18) the joints 
are nearly equal in size, elongated, subquadrate, each 
bearing five short setz, the larger of which are spine- 
like and plumose; in the male (Pl. LIX, fig. 16) the 
joints are much reduced in length and bear fewer sete. 
Caudal segments short, the outer tail seta about 
one third as long as the inner. Length, sth of 
an inch (1 mm.). 
This is an exceedingly distinct and graceful species, 
and is in general easily recognised by its long, curved 
antenne, and by the pyriform palm of the lower foot- 
jaw; 1t often occurs in considerable abundance. I 
have notes of its capture in the following places :—In 
surface-net, Westport and Roundstone Bays (abundant 
in the last-named locality); on Laminarie, Clifden Bay ; 
