082 Proceedings of the Royal Irish Academy. 
Lough Gill, Co. Kerry, River Bann, near Coleraine; Bellarena, Co. 
Derry. Brackish ditches near town of Galway. Portmarnock, Co. 
Dublin. 
Var. lanceolata, (Grunow). Marine or brackish water. 
Valve lanceolate, ends produced; relatively longer and narrower 
than the typical species. Length :0024, breadth -0008. 
Nayicula tumida, var. lanceolata, Grunow, Verhand. der K. K. 
Zool. Bot. Gesell., Band x., 1860, p. 537, T. iv. fig. 44. This as well 
as the preceding species, being both incidental to marine or brackish 
water, can scarcely be regarded as varieties of Navicula tumida, which 
is a fresh water species. 
Portmarnock, Co. Dublin. Breaches near Newcastle, Co. Wicklow. 
Nawicula tumida, (Wm. 8m.) Fresh water. 
Valve small, elliptical, with short capitate ends; intermediate free 
space narrow, slightly expanded in the middle; striz close, monili- 
form; convergent in the middle, and radiate towards the ends; 
length varying from ‘0018 to 0020; breadth from -0005 to -0008. 
Wa Sm.) Bed). Nol. :i.:) pegod,t Pl) xvii. te, LAGS orem. 
Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860, p. 537, T. iv., 
fig. 48a. Cleve, Om Svenska och Norska Diat., p. 226.—Navicula 
Angelica, Ralfs,’ in’ Pritch.,:p. 900. Rab. Fl. Hur, Alg., sect. 1, 
p. 193. . Donkin, N. H. Brit. Diat., p. 35, Pl. v., fig. 11e. 
Kilcool; streamlet in Powerscourt demesne, Co. Wicklow. Lough 
Mask, Tourmakeady, Co. Mayo. Ditch near town of Sligo. 
Var. linearis, (O’Meara). Fresh water. 
Similar to the typical form, but sides linear, ends slightly pro- 
duced; stria coarser, obviously moniliform, radiate; length -0011, 
breadth :0005. (Plate 32, fig. 15.) 
Lough Gill, Co. Kerry. Lough Mask, Tourmakeady, Co. Mayo. 
Navicula pulchra, (Gregory). Marine. 
Valve lanceolate ; intermediate free space narrow, expanded in the 
middle; strie distinctly moniliform, radiate; length :0027, breadth 
"0008. (Plate 32, fig. 16.) 
Gregory, Q. J. M. S., 1856, Trans., p. 42, Pl. v., fig. 7. Ralfs, in 
Pritch;, p. 906... Rab: Fl. Mur Ale, ssect.2., ps 1/6: 
Galway Bay near the town of Galway. 
