CUSHMAN: VINEYARD SOUND OSTRACODA. 
365 
with one proximal and one distal annulated seta on the front margin 
and a pair of short setae on the hind margin, with a third one just 
above the sensory appendage. This third joint is of the usual type 
in the male of this genus with its long spreading group of filaments, 
and from the ventral side at the base, a long annulated seta. Fourth 
joint with tw T o setae at the frontal distal angle and a longer one from 
the middle of the distal margin. Fifth joint very short, with five long 
annulated and sparsely ciliated setae. 
Antennae of the male (pi. 28, fig. 10) of the usual type for this genus, 
the swimming branch with nine setae, two on the last joint; the sec¬ 
ondary branch (pi. 28, fig. 11) with two short setae on the upper joint 
and the next with three stout tooth-like setae between which the end 
of the terminal claw fits when closed. 
The mandibular foot of the male (pi. 28, fig. 12) has a large basal 
joint; the second and third .are subequal, the former with three stout 
spinose setae on the inner margin and four slender setae, two long and 
two short, on the outer distal angle; the third joint with a large claw¬ 
like seta on the middle of the inner border and three minute spines on 
the distal anterior angle. Fourth joint short with a long claw-like 
appendage and with two or three minute spines as in the preceding. 
Last joint very short, bearing the long terminal claw with a short 
spine at its base. 
The caudal laniina of the male (pi. 28, fig. 13) is five-elawed with 
the posterior side of each claw heavily spinose, especially near the 
inner portion; spines in two longitudinal rows. 
Copulatory organ of the male (pi. 28, fig. 14) each half ending in a 
large, blunt chitinous hook with a secondary hook behind it, at either 
side of which are two sharply pointed spines, and near the upper end 
two short setae. 
Shell of the female (pi. 28, fig. 15) much more rounded than that 
of the male, the antennal sinus greatly reduced; surface similar to 
that of the male but less marked. 
Antennulae of the female (pi. 28, fig. 16) in general similar to those 
of the male but without the sensory appendage and the long annulose 
seta from the same point. The setae above the position of this ap¬ 
pendage are in the female long and slender. 
The secondary branch of the antenna of the female (pi. 28, fig. 17) 
is reduced to a single joint having at the tip a stout curved claw and 
just back from it a small pointed spine. 
