380 Proceedings of the Royal Irish Academy. 
Navicula cluthensis, (Gregory). Marine. 
Valve broadly elliptical, with rounded ends; ‘intermediate free 
space narrow, linear, but slightly expanded at the central nodule ; 
strie moniliform; puncta small, close, nearly parallel in the middle, 
and divergently radiate towards the ends; length, :0020; breadth, 
‘0013. (Plate 32, fig. 9.) 
Gregory, Diat. ot Clyde, p. 478, Pl. ix., fig. 2. Ralfs, in Pritch., 
pi f009, Blvcvu., 73. Rab. Fl. Eur. Alg., p. 184.—Navicula 
erythrza, me Newland der K. K. Zool. Bot. Geseil., Band x., 
1860,.p..589,:T. v., fied. 
River Slaney, near Killurin, Co. Wexford. Stomachs of Ascidians, 
Roundstone Bay, Co. Galway. 
Var. producta, (O’Meara). Marine. 
Precisely as the typical species, but having the ends slightly pro- 
duced; length -0025, breadth -0011. (Plate 32, fig. 9a.) 
Stomachs of Ascidians, Broadhaven Bay, Co. Galway. 
Navicula punctata, (Kiitz.) Fresh water. 
Valve elliptical, ‘ends produced, narrow, capitate ; intermediate 
free space narrow, except in middle, where it expands into a 
tolerably broad stauroform band, widening towards the outer end; 
strie moniliform; puncta small; radiate; length ‘0032, breadth 
0010. (Plate 32, fig. 10.) 
Donkin, N. H. Brit. Diat.; p. 36, Pl. v., fig. 12. Lagerstedt, 
Sotvat. Diat. fran Spetsberger och Beeren Eiland, p. 29.—Stauroneis 
putictdta, “Kitz.,: Bae., 7p.- LOO. 1 soa. ee Wea. route le 
Vol. 1., p: 61, Pl. xrx., fie. 169, “Nalts in, Priich.p. 912.. \aruuom, 
Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860, p. 565. Castra- 
cane, Catalogo di Diat. raccolte nella Val Intrasca, p.11. Cleve, 
' Om Svenska och Norska Diat., p. 228. Rab. Fl. Eur., Alg., sect. 
i., p. 245.—Stauroptera punctata, Rab. Siissw. Diat., p. 50, T. ix., 
ae ts 
River Slaney, near Killurin, Co. Wexford. Drumoughty Lough, 
near Kenmare, Lower Lake, Killarney, Lough Gill, Co. Kerry. 
Lough Mask, near Tourmakeady, Co. Mayo. Lough Mourne deposit, 
Co. Antrim. 
Navicula lacustris, (Gregory). Fresh water. 
Similar to Navicula punctata, but the striz are very much finer ; 
and the intermediate free space expanded roundly, instead of in a 
stauroform band; length about -0020, breadth -0006. (Plate 32, fig. 11.) 
Gregory, (Q. Ki M. Ss. 1856; p.o 6; Blas) figs 23.) describes 
two distinct varieties, one elliptical, the other with lmear margin 
and produced ends. He also refers to an intermediate form, which 
