O’Mrara—Report on the Irish Diatomacee. 317 
Pritch., p. 810, Pl. iv., fig. 51, 52. Grunow, Verhand, der K. K. Zool. 
Bot. Gesel., Band xii., 1862, p. 319. Rab. Fl. Eur., sect. 1, p. 300. 
Lough Derg, Co. Galway. Ulster Canal, near Newry, Co. Armagh. 
Only a few forms were found in these localities, the species being one 
of the rarest in Ireland. 
Genus II. Tasrnrarta, Ehr. 
Frustules attached in zig-zag filaments; valves expanded at the 
middle and ends; strize faint. 
Tabellaria flocculosa, (Roth.) Fresh water. 
Diaphragms numerous, thickened ends alternately placed, and 
varying in length. (PI. 29, fig. 3.) 
Kitz. Bac,, p. 127, T. xvu., fig. 21. Rab. Sussw. Diat., p. 63, 
ice ne 2a Wom. (br... Vol. i. Dy 40, -Pl., xli., fig. "316, 
Ralfs, in Pritch., p. 807, Pl. xii., fig. 29. Grunow, Verhand. der K. 
K. Zool. Bot. Gesel., Band xu., 1862, p. 410. Heiberg, De Danske 
Diat., p. 70. Castracane, Catalogo di Diat. raccolte nell Val Intrasca, 
p- 15. Cleve, Om Svenska och Norska Diat., p. 221.—Tabellaria 
ventricosa, Kiitz. Bac., p. 127, T. xxx., fig. 74, does not differ from 
the present species. 
Frequent, especially in sub-Alpine and boggy pools. Kiitzing re- 
gards this species as identical with Conferva flocculosa, Roth., on which 
authority the species is attributed to Roth. 
Tabellaria fenestrata, (Lyngb.) Fresh water. 
Diaphragms few, and of equal thickness on both sides of the cen- 
tral expansion ; frustules much longer than in the preceding specics. 
Koitac Bac...p. 127, Ro xvi, fig, 22 T) xvii. fe. 2, and T. xxx.) 
fig. 73, who regards the species as identical with Diatoma fenestratum 
Lyngbye. Rab. Siissw. Diat., p. 63, T. x., fig. 1. Wm. Sm., B. D., 
Vol. u., p. 46, Pl. xlvii., fig. 317. Ralfs, in Pritch, p.807. Grunow, 
Verhand. der K.K. Zool. Bot. Gesel., Band xii., 1862, p.410. Heiberg, 
De Danske Diat., p. 71. Castracane Catalogo di Diat. raccolte nell Val 
Intrasca, p. 16. Cleve, Om Svenska och Norska Diat., p. $21. 
Common in the same localities as the preceding, with which it is 
usually mixed. 
Genus III. Trrracyctrvus, Ralfs. 
Frustules united in parallel filaments; filaments free; thickened 
2P2 
