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Show |896.] BRITISH HYDROIDS AND MEDUSAE. 473 PART IL-MEDUSA WITHOUT OB WITH UNKNOWN HYDEOID FOBMS. These Medusae are arranged according to Haeckel's ' System der Medusen.' ANTHOMEDUSAE. Fam. CODONIDJE. DIPURENA HALTERATA (Forbes). Slabberia halterata, Forbes (1848); Cocks (1849). Dipurena halterata, Haeckel (1879); Browne (1895). I have occasionally met with one or two specimens of this interesting medusa. I saw one specimen at Plymouth on 25th September, 1893. The specimen was unfortunately in a bad condition, the umbrella being turned inside out. The basal bulbs of the tentacles were of a dark brown colour with a single deep crimson ocellus. At the free end of each of the four tentacles there was a very large knoblike cluster of nematocysts, and the upper half contained a dark brown pigment. A single specimen was taken at Valencia on 10th April, 1895. Umbrella about 1 m m . in length. Forbes describes and figures the gonads as slight swellings upon the radial canals. This statement requires confirmation. Haeckel, however, has taken a specimen at Jersey, which corresponded to Forbes's description, except that the gonads were upon the manubrium. Haeckel describes three swellings on the manubrium, one above the other, filled with sperm, the lowest swelling reaching nearly down to the mouth. DISTRIBUTION. Jersey, Haeckel. England-Plymouth, E. T. B. Falmouth, Cocks. Mounts Bay, Forbes. Isle of Man, Browne. Ireland-Valencia Island, E. T. B. DIPURENA, sp. ? (Plate XVI. fig. 2.) During m y visit to Plymouth in September, 1895, I obtained upon the 10th two specimens of a medusa which certainly belongs to the genus Dipurena. I regard them as early stages on account of medusa-buds being present upon the stomach. I have already shown in the cases of Amphicodon fritillaria, Margellium octo-punctatwn, and Lizzia blondina, that it is a characteristic feature of the young stages to bud off medusae, and in the adult stage to have gonads upon the stomach. I believe that Codonium gemmiferum and Sarsia prolifera, now regarded as distinct species, will be ultimately proved to be only early stages of other known species. I have not yet been able to trace these early stages of Bipurena |
