| OCR Text |
Show 1896.] BRITISH HYDROIDS AND MEDUSJE. 487 Mitrocomella polydiadema (Eomanes) is very much like Euchilota pilosella to the naked eye ; but it has sixteen marginal vesicles and no cirri upon the ex-umbrella. DISTRIBUTION. Scotland-Shetland Islands, Forbes. England-Plymouth, Garstang, Allen. Falmouth, Alder. Ireland-Valencia Island, E. T. B. EPENTHESIS CYMBALOIDEA, Haeckel. This is another mysterious medusa which has been handed down to us by the ancient naturalists. Slabber first described it under the name of Medusa cymbaloidea in 1775, and Shaw (1789) has copied Slabber's figures and also changed the name to Medusa campanella. To judge from the figures given, the medusa appears to be very much like Thaumantias hemisphcerica (Gronovius) with fewer tentacles. The generative organs occupy the outer half of the radial canals. The medusa was caught by Slabber in the act of swallowing a fish, tail foremost, of which a figure is given. Lamarck (1817) has copied Slabber's description, and Eschscholtz (1829) changed the generic name to Thaumantias. Blainville (1834) has given again Slabber's account of the species and copied his figures, but has left out tbe wonderful fish. Haeckel (1879) has placed all these references under the name of Epenthesis cymbaloidea, a genus of the Eucopidae,and characterized by the possession of 16 marginal vesicles and 16 tentacles. Amongst the synonyms Haeckel has placed Thaumantias thompsoni, Forbes, which is also given as a doubtful synonym of Thaumantias forbesii, Haeckel (Thaumantidae, Haeckel). The figure of Slabber's medusa bears no resemblance to Forbes's species, which is more like Phialidium buskianum (Gosse). It only requires the addition of the necessary marginal vesicles to make the identification complete. These Haeckel bas added. Eucope gemmigera, Keferstein (1862), is also given as a synonym by Haeckel of Epenthesis cymbaloidea. According to Keferstein this medusa has a ciliated medusa-bud upon the stomach. I prefer for the present to regard this medusa as a distinct species. The medusa-bud is not described in detah and the figure shows the externa] shape only. It may be a young stage of the parasitic Halcampa, which often attaches itself to the stomach or the generative organs of medusae. Epenthesis cymbaloidea, Haeckel, and its synonyms have no connection whatever with Phialidium cymbaloideum (Van Beneden). PHIALIDIUM VARIABILE, Haeckel. Under this name Haeckel has united several species which I consider to be quite distinct. H e gives no less than 26 references which are divided into two sets, one for the Mediterranean and the other for the Atlantic Ocean. Just as in the case of Thaumantias hemi'phcerica, the early writers omitted the marginal vesicles, which amongst the Eucooidae |
