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Show 1897. j - MR. E. T. BROWNE ON BRITISH MEDUSA?. 833 AGLANTHA ROSEA (Forbes). (Plate XLIX. figs. 1, 1 a, 1 b.) Circe rosea, Forbes (1848); M'Intosh (1890); Crawford (1891). Aglantha digitalis, Hartlaub (1894). Towards the end of April and during May 1895, I found in Valencia Harbour about a dozen specimens of an Aglantha with eight marginal vesicles. The specimens agreed fairly well with the description given by Forbes of Circe rosea, but Forbes has omitted, as usual, the marginal vesicles iu the description. During m y second visit to Valencia in 1896 I again met with examples of: the same species. Haeckel has placed Circe rosea, Forbes, as a synonym of Aglantha digitalis, a species first briefly described by Midler (1766) under the name of Medusa dlgitale. Haeckel bas again described the species and has stated clearly that there are always four marginal vesicles (" Horkolbchen ") present. The umbrella is 30-40 mm. in length and 10-20 m m . in width. Maas (1893) has also described Aglantha digitalis, taken by the German Plankton-Expedition, with four marginal vesicles. Hartlaub found in 1894, off Heligoland, specimens of a small Aglantha with eight marginal vesicles, which he briefly describes under the name of Aglantha digitalis (Midler), and gives Circe rosea, Forbes, as a synonym. I do not think that these small medusae, about. 12-14 m m . in length, with gonads and with eight marginal vesicles, are the young forms of the large medusa with four marginal vesicles described by Haeckel as Aglantha digitalis. I believe there are two distinct species, and that Forbes's description corresponds to the smaller one with eight margiual vesicles. I think that the name Aglantha rosea (Forbes) ought to be retained for the forms with eight marginal vesicles, and Aglantha digitalis for the forms with four vesicles. Notes on Specimens taken at Valencia. The smallest specimen was taken on 22nd July, 1896, about 1| m m . in length and nearly as wide. It had four margiual vesicles, the only specimen seen with four vesicles, and the tentacles, contracted, were of a bright red colour. The other specimens measured from 5 to 11 m m . in length, and all possessed eight marginal vesicles. The gonads in most of the specimens were just making their appearance and none exceeded 2 m m . in length ; all were immature. Several of the specimens possessed tentacles of a reddish colour, and in some the stomach and the lips of the mouth were of a pinkish colour ; but most specimens were quite colourless. The tentacles varied in number according to the size of the umbrella, about 60-80 present in the largest specimens. The description of a specimen taken on 22ud May, 1895 :- Umbrella cylindrical with a cone-shaped summit, 11 m m . long and 5 m m . wide. The manubrium reaches down nearly to the velum, aud a slight constriction marks the boundary between the |