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Show 52 MR. F. E. BEDDARD ON JEOLOSOMA TENEBRARUM. [Feb. 5, Soc. 1888, p. 213). I am also able to take this opportunity of announcing the occurrence in Ireland of Vejdovsky's species JEolosoma variegatum (" JEolosoma variegatum, Prispevek ku poznani nejnizsich Annulatuv," SB. bohm. Ges. Wiss. 1885), of which some examples were kindly forwarded to m e by Prof. Howes, who had himself received them from Prof. Hartog, of Cork. A comparison of JE. tenebrarum with JE. variegatum has convinced m e that, as I stated in m y paper, the affinities of JE. headleyi are with the latter species. In both these forms the epidermic coloured cells are bright green, while in JE. tenebrarum they range from greenish yellow to brownish olive. JE. tenebrarum, furthermore, differs from all other species of the genus in possessing (-shaped setae in the posterior segments of the body, in addition to the hair setse present in those segments and elsewhere: the setae are stated by Vejdovsky (loc. cit.) to be bifid at the free extremity, but I have not been able to see this in m y specimens ; in Vejdovsky's specimens the epidermic coloured cells are of a pale yellow, contrasting therefore with the specimens studied by myself, which 1 a m unwilling, however, to refer to a new species since they agree in all other particulars with JE. tenebrarum. This species of JEolosoma is extremely hardy if supplied with sufficient food. I have a large number of specimens which go on multiplying rapidly in a small bottle containing duckweed and a thin layer of vegetable debris at the bottom ; the worms have remained in this small vessel for several months, although there is a tolerably thick scum of Leptothrix and Bacilli upon the surface. O n the other hand, if deprived of food they soon die ; three specimens placed in a watch-glass containing water from the vessel in which they lived, but no appreciable quantity of vegetable debris, died in an hour and a half. The watch-glass was placed on a window-sill of north aspect. In these particulars JE. tenebrarum contrasts with JE. variegatum. I placed the specimens of the latter species in a bottle with abundant food ; the water and the duckweed were obtained from a locality where there were no specimens of AE. tenebrarum: one or two examples of the latter were, however, introduced by means of a pipette ; these multiplied to a great extent, and I have not been able since to discover a single specimen of JE. variegatum. The green-coloured spots of JE. tenebrarum are large cells with a thin peripheral layer of protoplasm containing a nucleus ; in the centre is a large globule of oily appearance impregnated with the colouring-matter. Vejdovsky has remarked (loc, cit. p. 65) that the globule is stained black with osmic acid, thus proving it to be of an oily nature. I have found that osmic acid produces a dark brown stain. The green colouring-matter naturally suggests chlorophyll; and Zacharias (" Studien iiber die Fauna des grossen und kleinen Teiches im Riesengebirge," Zeitschr. wiss. Zool. Bd. xii. pp. 499-500) states that in an JEolosoma (probably JE. variegatum) he observed the green bodies dividing, and therefore considers that they may be parasitic algae. With a view to discovering whether the bodies |