198 PROCEEDINGS OF SOCIETIES. 



time in this country on the late excursion to Connemara. It had 

 indeed, seemingly, as yet been found only in three sites (Raben- 

 horst's ' Flora Europcea Algarum Aquse dulcis et submarinae,' p. 

 36) : once by Braun himself at Freiburg, again near Berlin, and 

 once again by Itzigsohn at Neudamm. Of this little Alga, only 

 briefly described in a footnote by Braun, in his ' Algai-um uni- 

 cellularium Genera nov. et minus cogn.' (p. 4i), that author 

 furnishes no figure ; there is a woodcut given -by Kabenhorst (op. 

 cit., p. G, probably from slietches or specimens of Itzigsohn's ?), 

 but the figures there presented do not seem to grasp the true form 

 or structure of the cells in what would appear to be a full-grown 

 typical cluster or family. The upper or outermost cells do not, 

 as they are made to seem, or as the original description might lead 

 one to infer, stand above the larger and lower (inner) cells as 

 upon a common stipes, but the iovmev grow off" from the latter, 

 and remain joined thereto by a short pedicle (to convey some idea 

 one might say, to a certain extent, somewhat comparable to the 

 way in which young fronds in Lemna trisulca grow off from the 

 older ones). The inner cells are broadly reniform, and two stand 

 opposite each other at the apex of the supporting stipes, so as to 

 present a "lunate" figure, and from the lower part of the sinus 

 made by these it is that the pedicle of each of the pair of secondary 

 more or less reuiform, but unequally lobed, cells (one from 

 each lower cell) starts, the smaller lobes of these latter over- 

 lapping each other, and appearing, in a crowded cluster, like 

 one cell, only of smaller dimensions, concentrically posed above 

 the lower cell, and as if on a common stipes, that is, as if 

 all ■were " in ramulis .... quaternatim conjunctae." The larger 

 lower cells are combined, iiiter se, by a soft, irregular, colourless, 

 furcated (mostly as if '' shrivelhiV) stalk, into a crowded colony 

 or family. This branched cluster of cells requires to be broken 

 up and pressed out ere the arrangement referred to can be seen. 

 The structure and mode of arrangement of the cells (which, it may 

 be mentioned, are bright green, with a pale, narrow little space 

 at upper extremity, and with large chlorophyll-granules) becomes 

 thus of somewhat complex appearance, but without a figure it 

 would not be practicable, in Minutes like these, to convey a cor- 

 rect idea of this seemingly rather marked little plant. Nor does, 

 indeed, this arrangement of the cells, although there could seem- 

 ingly be no doubt of the identification, appear, one might venture 

 to think, to have been fully made out, even by Braun himself, for 

 his description {loc. cit.) does not seem to convey the points 

 which Mr. Archer tried to direct attention to in the examples 

 now under the microscope for exhibition. 



2^st Decemher, 1S71. 



Kev. E. O'Meara exiiibited the doubtfully distinct diatoma- 

 ceous lorm Pleurosigina pulclirum (Grunow), also an undescribed 

 form of the same genus, provisionally named Fl. mirahile, from. 

 Bantry Bay, found in collection thence obtained by Mr. More. 



