Onchotyle appendiculata from a dog-fish, [464]

Opossum, Echinorhynchus in a Brazilian, [434]

Opossums, flukes infesting American, [432]
"   much infested by nematodes, [433]

Orcella brevirostris, fluke found by Dr Anderson in, [417]

Orthagoriscus mola as a “host”, [471]

Ostrich, entozoa from the American, [447]

Otters, flukes and other entozoa of, [298]

Ox, insect parasites and tormentors of the, [351]
"  species of Strongylus infesting the, [347]

Oxyuridæ, a family of round worms, [5]

Oxyurides, sanitary precautions in respect of, [232]
"   source and mode of development of, [230]
"   voluntary swallowing of human, [72]