368 Proceedings of the Royal Irish Academy. 
Band x., 1860, p. 544, T. iii., fig. 28: and likely also identical with 
Nayicula limosa, var. bicuneata, Grunow, Verhand. der K. K. Zool. 
Bot. Gesell., Band x., 1860, p. 545, T. v., fig. 7. 
Lough Mask, near Tourmakeady, Co. Mayo. Kilcool, Co. Wick- 
low. Lough Guill, Co. Kerry. Pond in Botanical Gardens of Trinity 
College, Dublin. 
Navicula limosa, (Kiitz.) Fresh water. 
Valve triundulate on the margin, more expanded in the middle 
than at the ends; ends cuneate; strie fine, parallel; longitudinal free 
space narrow, except in the middle, where it is slightly expanded ; 
longitudinal ‘striz easily observed, with good illumination; length 
about ‘0084, breadth in the middle :0006. (Plate 31, fig. 30.) 
Kitz. Bac., p..101, T.m1., fie 50. Rab. Sisew. Diats pa L: 
vi., fig. 31. Ralfs, in Pritch., p. 894, Grunow, Verhand. der K. K. 
Zool. Bot. Gesell., Band x., 1860, p. 544, T. v., fig. 86. Donkin, 
N. H.. Brit. Diat., p..73, Pl. xii, fig. 61. Cleve, On Svenska och 
Norska Diat., p. 227. Lagerstedt, Sotv. Diat. fran Spetsbergen och 
Beeren Eiland, p. 30, T.1., fig. 6. 
Powerscourt, Co. Wicklow. _ Botanical Gardens of Trinity College, — 
Dublin. 
Var. gibberula, (Kiitz.) Fresh water. = 
Like the typical species, differig only in this, that the ends instead 
of being cuneate are rounded. 
Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860, 
p. 544, T. v., fig. 8a. Donkin, N. H. Brit. Diat., p. 73, Pl. xu.., fig. 6a. 
—Navicula gibberula, Kitz. Bac., p. 101, T.in., fig. 50. Wm.Sm., 
B. D., Vol. 1., p. 51, Pl. xvu., fig. 160. Schumann, Diat. der Hohen 
Tatra, p. 76. Lagerstedt, Sotv. Diat. fran Spetsbergen och Beeren 
Filand, p. 38. 
River Erne, Crossdoney, Derrylane Lough, Co. Cavan. Glengar- 
riff, Co. Cork. Lough Neagh, near Lurgan, Co. Armagh. Streamlet 
in Powerscourt demesne, Co. Wicklow. Lough Mourne deposit. 
Var. truncata, (Kiitz.) Fresh water. 
Valve nearly linear, with rounded ends; the longitudinal sulci 
waved; length :0025, breadth -00055. (Plate 31, fig. 31.) 
Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860, 
p- 545, T. v., figs. 8e and 9.—Navicula truncata, Kutz. Bac., p. 96, 
To i., fig. 34, andl. ‘y,, fig. 4. Rab. Sussw- Dias, pi o9 ete 
fie. GT: 
Friarstown, River Dodder, Co. Dublin. Lough Neagh, near Lur- 
gan, Co. Armagh. Lough Mask, near Tourmakeady, Co. Mayo. 
Dundalk, Co. Louth. Wet rock, Ballyshannon, Co. Donegal. Castle- 
Gregory, Co. Kerry. 
