THE ANNALS AND MAGAZINE OF NATURAL HISTORY, [SECOND SERIES.] No. 83. NOVEMBER 1854. XXIX. — Contributions to the Natural History of the Infusoria. ^^\&>^^*^S£^ ^Y ^' Schneider*. * y^^^iy^n T\ [With a Plate.] ""^^^po. t4\d'^^''* I' ^'^ Polytoma Uvella. Polytoma Uvella is given by Ehrenbergf as the only species of the genus Polytoma^ and characterized in the following words : — " Animal e familia Monadinorum, ocello destitutum, ore termi-nali truncato, ciliis aut proboscide subtili flagelliforme duplici instructo natantibus solitariis antico, divisione spontanea decus-sata et imperfecta, multipartitum in Mori formam enascens, dein partitum et altera vice solitarium.^^ In a subsequent passage he adds — '^With regard to its organization the polygastric ali-mentary organs appeared distinctly. Besides these I perceived a larger contractile vesicle, which did not belong to the nutritive apparatus, and which appeared to be connected with the male sexual organs. Lastly, a large, free, white spot in the anterior part of the body, the outline of which could not be made out distinctly, but which pressed the stomachal sacs towards the hinder extremity, led to the supposition that a seminal gland existed in that place.^^ After repeated failures he succeeded, but only by employing a magnifying power of 6-800 diameters, in seeing the little sacs of the posterior portion filled with indigo. Dujardin, apparently, has never examined Polytoma himself, as he could not repeat Ehrenberg^s observations upon its mode of division J, and I am unacquainted with any subsequent obser-vations upon this creature. * Translated from Miiller's Archiv, 1854, p. 191. t Die Infusorien als volkoramene Organismen, &c., p. 24. X Dujardin, Hist. Nat. Infusoires, p. 276. Ann. ^ Mag. N. Hist. Ser. 2. Vol. xiv. 21
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