Birge—Notes on Cladocera. 
1043 
The remainder of the exopodite is a plate with two (Daday 
finds three) small projections on the ventral edge. These are 
apparently the rudiments of the other setae of the exopodite. 
The endopodite consists chiefly of a long, curved, plumose 
seta. A second, much smaller seta arises from the inner face 
of the base of this, and close to the insertion of the second 
seta is a small projection. I have not been able to find any 
part of the maxillary process, though it may possibly be pres¬ 
ent. The branchial sac is very large and is oval in form, 
as in the preceding feet. Daday finds it heart-shaped in W. 
pannanica. 
This foot closely resembles the corresponding appendage of 
Bunops and in most particulars that of Grimaldina. 
My interpretation of the morphology of this appendage is 
not that of all authors; nor are their judgments wholly con¬ 
sistent with themselves; as may be seen by following the ac¬ 
count of the fifth foot in the various genera of Cladocera, as 
given by Lund and Lilljeborg. All agree that the large, re^ 
curved seta belongs to exopodite. There is wide divergence 
as to whether the plate- to which this seta is attached is ex¬ 
opodite, or whether it is endopodite or maxillary process. If 
the fifth appendage of Bosmina is studied and compared with 
that of Wlassicsia (see Lund ? 71, PI. IX, fig. 15; Lilljeborg 
7 00, PL XXXVIII, fig. 14) it will be difficult to reach any 
other conclusion than that which I give. 
There is a well developed abdominal process of rather irregu¬ 
lar form. The abdominal setae are long, 2-jointed, sparsely 
plumose on the outer joint. The piostabdomen (PI. LXX1, 
fig. 2) is large, broad, with a thin dorsal edge, and is bilobed. 
The pro-anal lobe has numerous small spines along its dorsal 
edge, giving it a serrate appearance near the abdominal setae. 
The anal lobe has numerous clusters of fine hairs. The ter¬ 
minal claws (PI. LXX, fig. 8) are small, relatively stout, 
denticulate, and have a small basal spine. 
The intestine has no convolutions, and bears two hepatic 
coeca. (PI. LXIX, fig. 4) The eye is large, with abundant 
pigment and few lenses. The ocellus is rather small, quadrate 
as seen from the side. 
