of Monotus fuscus with littoral animals, [46];
significance, in Turbellaria, [51]—see also Commensal and Parasitic
Asteroids, as hosts, [341]
Asterope, [315]
Astropecten, as host, [297], [309]
Atokous phase, [277] n.
Atractonema, [131], [150], [152], [153]