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Show 482 MB. E. T. B R O W N E O N [Mar. 17, be easily recognized. The other fourteen species of Thaumantias form a miscellaneous group, which, owing to their vague descriptions, have caused a considerable amount of trouble to recent writers on Medusae. Haeckel has divided these species amongst two families- Thaumantidce and Eucopidce-the former characterized by the absence of marginal vesicles, and the latter by the possession of them. Forbes has omitted the vesicles in the descriptions and figures of nearly all his species, and according to his views they were worthless for specific characters. If Forbes had onlv added these important organs to his drawings, which have been rendered almost useless by their omission, tbe present confusion would never have arisen. It is clear that Forbes has seen the marginal vesicles in some of the species, as in his monograph (p. 9) he writes:-" I have observed the vibration of the otolites distinctly in more than one species of Thaumantias." After the publication of Forbes's monograph the name of Thaumantias hemisphcerica appeared on most lists of Medusae, usually without any description of the medusa. Since the appearance of Haeckel's monograph the name has gone out of fashion, and Phialidium variabile has taken its place. For three years I have searched for Thaumantias hemisphwrica and the allied species, also without marginal vesicles, but without any success. Every specimen, which has the slightest resemblance to one of Forbes's figures, possesses marginal vesicles. I may here add that specimens preserved in alcohol are not to be relied upon for the absence of marginal vesicles in the living medusa; the vesicles ofteu shrivel up and the otoliths disappear. LAODICE CRUCIATA (Forskal). Haeckel has placed under the name of Laodice cruciata no less than twenty-five synonyms, which are divided into two groups-one for the Mediterranean form of Laodice cruciata, and the other for the Atlantic form. The synonyms of the Atlantic form may be divided into two sets, one referring to Medusa cvquorea, Baster (1759), the other to Thaumantias pilosella, Forbes (1848). Medusa cequorea, Baster (1759); Linnaeus (1767). Callirhoe basteriana, Peron and Lesueur (1809); Eschscholtz (1829); Blainville (1834). The original descriptions and figures of this medusa given by Baster, and copied by other writers, without any additional information, appears to m e to be too vague for the purpose of identification. The drawings clearly show that the sub-umbrella has been injured, as the stomach and some of the bauds of gonads on the radial canals are in a damaged condition. Whatever kind of medusa Baster had under observation, the description and figures appear to be too vague to identify it with any species known to us at the present day. |
