1026 Wisconsin Academy of Sciences, Arts, and Letters. 
semi-ellipsoidal enlargement or bulb, densely covered with short 
hairs, and against which the tip of the claw shuts. In the 
hollow of the clasping apparatus thus formed and arising from 
the enlargement of the base is a rather large, transparent, 
tapering seta, very delicate in structure and apparently sen¬ 
sory in function. This clasping apparatus may be regarded as 
a development of that found in Sida. (See Lilljeborg, ? 00, 
p. 26) ; or it resembles even more closely that of L. fascicu- 
lata as described later in this paper. Sida (Lilljeborg, PL 
II, fig. 3) shows a clasping structure with an enlarged and 
hairy bulb at the base and a hollow between hook and base; 
the hook is blunt and finger-like. In Latonopsis (PI. LXVII, 
figs. 6,7) the hook is a claw, which bends over against the basal 
part without leaving a hollow. In L. fasciculata the basal 
part is enlarged and hairy but does not have the hollow found 
in Pseudosida. Along the inner side of the clasper and pro¬ 
jecting beyond it is a long, tapering, thin-walled, rather soft 
extension of the terminal part of the endopodite (PL LXVII, 
fig. 7). This has near its base several long two-jointed setae 
like those on the edge of the endopodite and forming part of 
that series. This structure, which I suppose is chiefly sensory 
in function, is quite like the corresponding part of the male foot 
in both species of Latonopsis. Daday, in describing P. var¬ 
iabilis (’05, p. 223) calls this organ “eine machtige sichel- 
fformige Kralle”, but in my specimens it is certainly not a claw; 
on the contrary, it is thin-walled and filled with soft material 
which shrinks away from the wall in preserved specimens. 
Daday also refers to what I have called a sense-seta inside the 
claspers as “ein kraftiger Dorn”. These two small differences 
in the thickness of walls of parts of the male clasping appara¬ 
tus are the only tangible differences that I can find between 
Daday’s description and figures of P. variabilis and my speci¬ 
mens of P. bidentata. I, therefore, with some hesitation, re¬ 
gard the two species as identical. If not so, variabilis can 
have hardly more than varietal rank. The genus Pseudosida 
is a tropical one, as is evidenced by its presence in Ceylon, 
Siam, Sumatra, and South America. Its presence on the 
