Page:Journal of botany, British and foreign, Volume 34 (1896).djvu/26

 10 SOME NEW BRITISH MARINE ALG^. found at Falmouth, at the meeting of the Linnean Society on Nov. 21st, 1895. Trailliella, nov. gen. Fronds composed of monosiphonous, branching, jointed filaments. Primary filaments procumbent, attached to the substratum by disc-shaped cells. Secondary filaments arising from the primary filaments, erect, branching. Tetraspores immersed, formed from a portion of the cell -contents of cells in the continuity of the frond, irregularly cruciate ; cystocarps and antheridia unknown. The tetraspores are formed in an analogous manner to the monospores of lihoduchccte [vide Bornet, Les Algiies de P. K. A. Schousboe, p. 361). The cell in which a tetraspore is formed swells, and its cellular contents divide longitudinally into two parts of unequal size, the larger of the two parts becomes darker in colour, more opaque and granular, and at the same time increases in size until finally it fills almost the entire cell, when it divides into two parts by a transverse division, and ultimately forms an irregularly cruciate tetraspore. The systematic position of the genus must of course remain doubtful so long as the cystocarps are unknown, but in the meantime the genus may be placed next to Spermothamnion. Trailliella intricata, nov. sp. Fronds forming dense, rose-red or brownish-red tufts. Primary filaments 30-40 /x thick, irregularly branching, attached by disc-shaped cells. Secondary filaments erect, ^-1^ in. high, and of nearly equal diameter (30-45 /x) throughout, simple or branching, more or less naked below, pin- nate above, with alternate or subsecund spreading branches of almost the same diameter as those from which they arise, tapering at the apex to about 20 /x. Cells of both the primary and secondary filaments 1^-2^ times longer than broad, more or less swollen in the middle ; in most of the cells one of the upper corners is occu- pied by a small roundish or triangular refractive colourless body 12-15 fM in diameter, which is probably analogous to the refractive bodies so often found in species of Antithamnion. Tetraspores immersed in the swollen cells of the secondary filaments, 50-60 /x in diameter, solitary or 3-6 together, formed from successive cells of the filament, separated from the apex of the filament by from 3 to 15 unchanged cells. Plymouth, October, 1895, G. Brehner. Studland, Sept. 1890, E.M.Hohnes; Sept. 1895, E.A.B. This very interesting species has long been known in a barren con- dition, and is the Spermothamnion Turnerii. intricata of Mr. Holmes's and my Revised List, and I have every reason for believing that it is S. intricatum J. Ag. It was reserved for Mr. Brebner, however, to discover the tetraspores, which are placed quite differently from those of any other member of the Ceramiece known to me, thus necessitating the removal of this plant to a new genus ; and I have seized the opportunity to connect the name of my friend Mr. G. W. Traill, the well-known algologist of Edinburgh, with the British Marine Flora for which he has done so much. I must here express my regret that Mr. Brebner has not seen his way to allow any of the new genera discovered by him to bear his name. If Mr. Brebner goes on as he has commenced at Plymouth, however,