in Cyclostomata, [479], [480], [521], [525]

Oviduct—see Ovary

Owenia, [325]

Ox, parasites of, [79], [83], [125], [139], [140], [143]

Oxysoma, [139], [142]

Oxyuris, [129], [131], [135], [139], [141], [160];

O. ambigua, [141];

O. curvula, [141], [163];

O. diesingi, [141], [142];

O. vermicularis, [141], [163];