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Show 476 MR. E. T. BROWNE O N [Mar. 17, Lizzia blondina has, in the adult stage, four perradial groups of three tentacles and four single interradial tentacles. The increase of new tentacles is shown in the following list. Specimens collected by M r . Garstang at Plymouth during July and August, 1893 :- Perradial tentacles.... 1111 (Q specimens)> Interradial tentacles .. 1111 Perradial .... m ? 2211 2121 2222_ Interradial .. 1111' 1111' 1111' H H O n m y arrival at Plymouth at the end of August, 1895,1 found Lizzia fairly abundant in the tow-net, but no specimens were taken after the second week in September. The following list drawn up from these specimens shows the increase of the tentacles :- Perradial.... 1112 2121 2221 2222 2223 3332 Interradial.. llll' 1111' 1111' 1111' n i l ' llll" At Valencia, 1895, Lizzia appeared in the tow-net a few days before m y departure at the beginning of June. I only obtained a few specimens, which possessed the following number of tentacles:- Perradial.... 2222 2223 3333 Interradial .. llll' llll' llll* The umbrella of the earliest stage is about 1 mm. in length and nearly as wide, with a slight transverse constriction above the sub-umbrella. The largest specimens are about 1± m m . in length. Nearly every specimen belonging to the early stage has medusa-buds upon the stomach. One of the largest specimens taken at Plymouth had a mass of ova surrounding the walls of the stomach. The budding of medusae is followed by sexual reproduction, just as in many other medusae. There are always four simple oral tentacles, each terminating in a large cluster of nematocysts. I have never seen more than one cluster of nematocysts upon each oral tentacle, and always four single interradial tentacles. These points distinguish Lizzia blondina from Margellium octopunctatum. Abnormal Specimen.-An abnormal specimen was taken at Plymouth on 31st August, 1895, with 3 radial canals, 3 oral tentacles, 3 groups of perradial tentacles, with 2 tentacles in each, and 3 single interradial tentacles. Claparede described and figured a form of Lizzia, which Haeckel has regarded as a distinct species and has placed it in his monograph under the name of Lizzia claparedei. The medusa has four perradial groups of two tentacles, and four single interradial tentacles; four simple oral tentacles, each terminating in a cluster of nematocysts. Ova upon the walls of stomach. The shape of the umbrella resembles that of Lizzia blondina. |