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Show 464 MR. E. T. BROWNE ON [Mar. 17, Sars* (1877); Haeckel (1879); [medusa = Hybocodon nutans] Haddon (1885) ; Hincks (1886); Hartlaub (1894); Allen* (1895). Corymorpha galanthus, Haeckel (1879). Medusoid Form. Corymorpha nutans, Allman (1863); Garstang (1894); Crawford (1895). Steenstrupia rubra, Forbes (1848); Peach (1849); Haddon (1885) ; Browne (1895). Steenstrupia fiaveola, Forbes (1848). Steenstrupia galanthus, Haeckel (1879); Hartlaub (1894). The hydroid form of Corymorpha nutans with medusa-buds was first described by Sars from specimens taken on the Norwegian coast. Forbes and Goodsir a few years later added the hydroid to the British list by finding specimens off the Orkney Islands. Hodge bas described specimens from Seaham Harbour and Allman from the Firth of Forth. Allman, Hincks, Hodge, and Johnson consider the British species to be that described by Sars, and call it Corymorpha nutans. Haeckel, however, states that the Norwegian species is quite distinct from the British species. He retains the name Corymorpha nutans for the Norwegian hydroid and calls the medusoid Hybocodon nutans. The English species has been given the new name of Corymorpha galanthus and its medusoid called Steenstrupia galanthus; under the latter name Haeckel places the medusoid Steenstrupia rubra, Forbes, as a synonym. This separation is entirely based upon the shape of the umbrella of the medusa. Sars described the young medusa upon the hydroid as having an oblique margin to the umbrella, like Hybocodon pro-lifer. This has led Haeckel to place the medusa in the genus Hybocodon. Haeckel apparently, judging from his references, has only read the description of the English species in the monographs by Hincks and Allman. In these, the margin of the umbrella is described and figured as occupying its normal position at right angles to the longitudinal axis of the umbrella, and no mention is made of the obliqueness of the margin of the umbrella of the medusa whilst attached to the hydroid. But in the original papers published by Hodge (1861) and by Allman (1863) on the hydroid Corymorpha, the medusa is described with an oblique margin to the umbrella; it therefore corresponds with the description given by Sars. Hodge gives figures of the medusae upon the hydroid, and the margin is shown to be distinctly oblique. He not only figures the medusae upon the hydroid but gives an excellent figure of the free-swimming form, just liberated from the hydroid kept in his aquarium. The free-swimming medusa, as figured by Hodge, has the margin at right angles to the longitudinal axis of the umbrella ; therefore it cannot be oblique. Allman (1863), in his original description of Corymorpha, on the development of the medusa states :-" The four peripheral processes continue to |