368 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
from the apex of the antepenultimate a group of five setae; first pair 
of feet 5-jointed, claw long; second pair 4-jointed; abdominal rami 
with two curved claws at the apex besides setae. 
Pontocypris edwardsi sp. nov. 
PL 30, fig. 26-34. 
Shell, seen from the side, subtriangular, highest in the middle, 
height equal to more than half the length; dorsal margin strongly 
arched, highest in the middle; seen from below, the outline is ellip¬ 
tical, widest in the middle; valves smooth, thickly clothed with fine 
hairs. 
Antennulae with four setae from the basal joint; antennae of the 
usual type for the genus; terminal claw of the maxillary foot long 
and slender, at least equalling in length the preceding three joints; 
terminal claw of the first pair of feet very long and slender, somewhat 
less than the total length of the preceding four joints, pectinated 
toward the outer end; pectinated seta of the second foot of medium 
length with at least twelve secondary processes; abdominal ramus 
with the outer of the two terminal claws only about one half the length 
of the inner one. 
Length 0.85 mm.; height 0.47 mm. 
Habitat .— Collected in considerable numbers in the Eel Pond, 
Wood’s Hole, August 22, 1905, from material seined by Mr. Vinal 
N. Edwards and the writer. All the specimens dissected were females. 
This was the only species present at this date, although a few weeks 
previously, in exactly the same part of the pond and at the same time 
of day, two other species were taken while the one here described was 
not seen at all. The European species of this genus seem to prefer 
muddy bottoms of protected or even brackish bodies of water. Our 
species is therefore very similar in its habits, for it was found nowhere 
in the region during the summer’s collecting except in this one locality, 
the Eel Pond, where such conditions prevail. 
FAMILY CYTHERIDAE. 
Shell usually hard and calcareous, surface typically rough or sculp¬ 
tured;' antennulae and antennae not fitted for swimming, the latter 
lacking the long brush of setae present in the foregoing family; three 
