1. Arai MN, Brinkmann-Voss A (1980) Hydromedusae of British Columbia and Puget Sound. Can Bull Fisheries Aquatic Sci 204:1?192
2. Ballard WW (1942) The mechanism for synchronous spawning in Hydractinia and Pennaria. Biol Bull 82:329?339
3. Berking S (1984) Metamorphosis of Hydractinia echinata: Insights into pattern formation in Hydroids. Wilhelm Roux's Arch 193:370?378
4. Blinks JR, Prendergast FG, Allen DG (1976) Photoproteins as biological indicators. Pharmacol Rev 28:1?93
5. Bodo F, Bouillon J (1968) Étude histologique du developpement embryonnaire de quelques hydroméduses de Roscoff: Phialidium hemisphaericum (L), Obelia sp. (Peron et Lesueur), Sarsia eximia (Allman), Podocoryne carnea (Sars), Gonionemus veritans (Agassiz). Cah Biol Mar 9:69?104