CUSHMAN: VINEYARD SOUND OSTRACODA. 
375 
Cytheridea americana sp. nov. 
PI. 33, fig. 67; pi. 34, fig. 68-75. 
Shell, seen from the side, elongate, highest in front of the middle, 
height less than half the length; dorsal margin gently arched in the 
middle, sloping very abruptly at the posterior end to form a dorso- 
posterior angle; anterior end more evenly rounded; both ends of the 
shell extended at the ventral portion; seen from above, elongate- 
ovate, widest in the middle, both ends somewhat truncately rounded; 
surface of the shell punctate, with large, irregularly scattered impressed 
areas with one or more masses of pigment in each, these areas most 
abundant anteriorly; besides these the anterior half has about nine 
large lucid spaces. 
Antennulae with three groups of hairs on the second joint; antennae 
of the usual type, but without the short setae in the middle of the outer 
border of the third joint; claw of the mandible with the outer tooth 
much longer than the others, otherwise much like that of C. rubra; 
feet slender with the second joint of the left foot in all three pairs with 
hairs on the outer border, posterior seta of first joint of first foot large 
and club-shaped; copulatory organ of the male with a very large, oval, 
basal mass, outer portion somewhat sharply acuminate. 
Length of the shell 1 mm. 
Habitat .— Dredged alive from the deeper part of Vineyard Sound, 
“Fish Hawk” station 7723. 
The surface characters of this species, with its fine punctae, coarser, 
impressed, pigmented areas, and the larger lucid areas will serve to 
distinguish it. 
Genus Cythereis Sars. 
Cythere, in part, of authors. 
Cythereis Sars, ’66, p. 35; G. W. Muller, ’94, p. 364. 
Shell strongly calcareous, usually richly sculptured; antennulae 
usually 6-, rarely 5-jointed; antennae 4-jointed, flagellum short in 
the female; mandibular palp 4-jointed; first pair of feet differing 
on the two sides of the body in the male. 
