O’Mrara—Report on the Irish Diatomacee. 407 
1 + Radiose. Strie more or less distinetly radiate. 
Navicula radiosa, (Kiitz.) Fresh water. 
Valve lanceolate, obtuse; strie strongly costate; convergent in 
middle, radiate towards the ends; length about -0020, breadth about 
"0005. (Plate 34, fig. 3.) 
Keuz.. Bacs, p. Ol,eT. iv.) fig. 23; Ralfs, in Pritch., p. 965. 
- Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860. Cleve, 
Om Svenska och Norska Diat., p. 225. Lagerstedt, Sotv. Diat. fran 
Spitzbergen och Beeren Eiland, p. 25.—Pinnularia radiosa, Wm. 
pms ED Vol. z, ps. 56, PL xvii, fie? 175.. Rab. Fl. Eur. Ale... 
sect. 1., p. 214. 
Pool, Glengariff, Co. Cork. Lower Lake, Killarney, Co. Kerry. 
Stream Crossdoney, Co. Cavan. River Dodder, Bohernabreena, Glenas- 
mole, Killakee, Co. Dublin. Lake near Castlewellan, Co. Down. 
Navicula gracilis, (Ehr.) . Fresh water. 
Valve lanceolate, attenuated towards the ends, which are obviously 
produced ; strize costate, convergent in the middle, radiate towards 
the ends; length about :0022, breadth about 0005. (Plate 34, fig. 4.) 
Kutz, Bac., ‘p. 91, VT.» fig: 48, TS xxx.; fig. 57, who regards 
the species described by him as identical with Navicula gracilis, Ehren- 
berg, Infus., 1838, p. 176, T. xi., fig. 2. Smith is doubtful as to 
the identity of the form described and figured by him with that of 
Kiitzing just referred to and comparison of the figures of Kiitzing 
with specimens of the form, so accurately delineated by Smith will 
impress something more than doubt upon the observer’smind. Ralfs, 
in Pritch., p. 906. Grunow, Verhand. der K. K. Zool. Bot. Gesell., 
Band x., 1860, p. 526, T. iv., fig. 27. The species is broader, more 
attenuated at the ends, than this figure represents it. Schumann, Diat., 
der Hohen Tatra, p. 69. Rab. Fl. Eur., Alg., sect. i., p. 174.—Pin- 
nularia gracilis, Wm. Smith, B. D., Vol.i., p. 57, Pl. xviii., fig. 
174. 
Drumoughty Lough, near Kenmare, Co. Kerry. Stream, Bellarena, 
Co. Derry. Stream near Crossdoney, Co. Cavan. Stream, Killiney, 
Stream, Ballybrack, Co. Dublin. 
Navicula acuta, (Wm. Smith). Fresh water. 
Valve, narrow, lanceolate; ends acute; striz costate, convergent 
in the middle, radiate towards the ends; length -0046, breadth -0005. 
(Plate 34, fig. 5.) 
Pintulara: acuta, Wms Sm., B.D:; . Vol. 1:5. p..56, Pl.xvin:, 
fig. 171.—Navicula radiosa, var. acuta. Grunow, Verhand. der K. 
K. Zool. Bot. Gesell., Band x., 1860, p.526. Thereisa form described 
