. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . iCRANOCHiETE^E. This sub-family includes only the singlegenus Dicranoch&te Hieronymus (1892), which differs from all the othermembers of the Planosporacea? in the possession of bristles. The latter arealso of a unique character, being dichotomously branched; bristles of such anature are entirely unknown in any other group of Algse (consult fig. 139).The cells are solitary and attached to the leaves of submerged species ofSphagnum and Hypnum;
. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . iCRANOCHiETE^E. This sub-family includes only the singlegenus Dicranoch&te Hieronymus (1892), which differs from all the othermembers of the Planosporacea? in the possession of bristles. The latter arealso of a unique character, being dichotomously branched; bristles of such anature are entirely unknown in any other group of Algse (consult fig. 139).The cells are solitary and attached to the leaves of submerged species ofSphagnum and Hypnum; they are uninucleate and possess a single massivechloroplast with or without pyrenoids. In D. reniformis Hieronymus (92) 1 The Archimycetes (ChytridieEe) show many striking resemblances to Chlorochytrium. Charaeieae 213 the bristle (or seta) arises from the base of the cell and passes upwards alonga lateral groove, but in D. britannica G. S. West (12) it is dorsal in itsattachment. Reproduction occurs only by biciliatecl zoogonidia (fig. 139 C),formed 4 to 32 in a mother-cell, and liberated in D. reniformis by the detach-ment of a special Fig. 139. Dicranochsete reniformis Hieronymus. x 1170 (lifter Hieronymus). A, cell showingdichotomously branched bristle. B, cell showing the cushion of mucilage (in) in which it islodged and by which it is attached ; n, nucleus ; py, pyreuoids. C, zoogonidium. Sub-family CHARAClEyE. The Alga? included in this small group areunicellular and generally occur as epiphytes, either solitary or in clusters, onother larger Alga?. The vegetative cells are rounded or angular in Sykidion.(fig. 141 F and G}, but in the other genera they are distinctly stalked, inwhich case there is a differentiation into base and apex. The largest cells(up to 1 mm. in length when mature) are met with in Codiolum, in which thecell-body is ovoid and the base drawn out into a solid stalk of some Characium (fig. 140) the cells are ovoid or fusiform, som
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