Arhynchidae, [185]

Arhynchus hemignathi, [181], [185]

Aricia, otocyst, [273];

eggs, [275]

Ariciidae, [258], [321];

gill, [265]

Aristotle, on Earthworms, [347]

Armata, [445], [446]

Arthropoda, absence of cilia in, [124]

Articulata, [517], [518]