nematocysts of, [247];
species of, [256];
specific gravity of, [13] n.;
host of Kerona and Trichodina, [158];
Zoochlorella in, [126], [256];
H. oligactis (= fusca), [253], [256];
H. pallida, [256] n.;
H. vulgaris, (= grisea), [253], [256];
nematocyst, [247]