er 
346 Proceedings of the Royal Irish Academy. 
Diat., p. 42, T. vi., fig. 19. Do. Fl. Kur. Alg., sect. 1, p.216 (where it is 
identified with Pinnularia latestriata.) Gregory Q. J. M.S., Vol. ii., 
1854, Pl. iv.,dig.j13,, )Wm. Sm..B.D, Wol, a. pag) 
Drumoughty Lough, near Kenmare, Co. Kerry. Pond near Glen- 
chree, Co. Wicklow. Ulster Canal, near Poyntzpass, Co. Armagh. 
Loughbrickland, Co. Down. Cushenden, Lough Neagh, Co. Antrim, 
Featherbed Mountain, Co. Dublin. 
Javicula menapiensis, N.S. Marine. ‘ 
Valve small; length :0016; breadth :0005; linear, ends rounded 
and slightly conical. Coste marginal, distant; intermediate free 
space tolerably wide, linear elliptical. (Pl. 30, fig. 15.) 
This form is, in some respects, similar to the “last, but strize are 
longer; otherwise distinguished by its marine habitat. 
Sea-weeds, Bannow, Co. Wexford. Stomachs of Ascidians, Broad- 
haven Bay, Co. Galway. 
Navicula tabellaria, (Ehr.) Fresh water. 
Valve oblong, slightly expanded at the middle and ends. Length 
about °0050; breadth about ‘0007. Coste strong, convergent in the 
middle, then parallel and radiate towards the ends; intermediate free 
space wide, roundly expanded in the middle. (Plate 30, fig. 12.) 
Kitz. Bac., p. 98, T. xxvii., figs. 79, 80, where the costz are- 
described incorrectly as reaching the median line; also T. xxx., fig. 
20, where the cost are represented as marginal, whereas they extend 
much further towards the median line. Grunow, Verhand. der K. K. 
Zool. Bot. Gesel., Band x., 1860, p. 516. Ralfs, in Pritch., p. 896, 
Pl. xu., fig. 21. Cleve, Om Svenska och Norska Diat.; p. 224. 
Donkin., N. H. Brit. Diat., p. 70, Pl. xu., fig. 4.—Pmnularia 
tabellaria, .Ebr. (Wm. (Sm., BoD) Voloi. ps 58) Pies, tees 
Rab. Siissw.. Diat., p. 44, T. vi., fig. 24. Do. Fl. Eur. Alg., sect. 1., 
pe 2 
Friarstown, Piperstown, Featherbed Mountain, Killakee, Co. 
Dublin. Glenchree, Lugnaquilla Mountain. Co. Wicklow. Glencar, 
Co. Kerry. Lough Corrib, Co. Galway. Lough Mourne deposit, Co. 
Antrim. 
Navicula tabellaria, var. acrospheria, (De Bréb.) Fresh water. 
Like the typical form. The costs, however, are marginal. 
Navicula acrospheria, Kiitz. Bac., p. 97, T. v., fig. 11, where 
it is alleged that the form is identical with Frustulia acrospheeria, 
De Brébisson, to whom, on this account, I attribute the species. 
Ralfs, in Pritch., p. 896.—Navicula tabellaria, Grunow, who observes, 
that ‘‘ Wm. Smith’s figures and descriptions of Navicula acrospheeria 
and N. tabellaria differ only in the different size and the somewhat 
