Aurophore, [308]

Autodermin, [523]

Automatic processes, so-called, [12]

Autotrophic, [37]

Autozooids, [333]

Axial filament, of Heliozoan pseudopodia, [49], [71], [72], [74];

of Actinophrys sol, [71];

of Actinosphaerium eichornii, [72];

of Radiolaria Acantharia, [80]

Axial sinus, of Asterias rubens, [448];