Although medusa‐release was first seen inObeliain the mid‐18th century (Baster, 1762b), the true nature of medusa‐release in any coelenterate was not understood until Sars' (1829) observations on a scyphozoan scyphistoma. A flourish of work followed during which many coelenterate life‐cycles were worked out, that ofObeliabeing among the first (by van Beneden, 1843). The impact on some areas of zoological thought of the mid‐19th century was considerable. Around the 1880sObeliabecame used in teaching to illustrate and introduce the concept of alternation of generations and, alongsideHydra, as a “type” example of the Hydrozoa and of the Coelenterata. It remained important as a teaching organism f