302 Proceedings of the Royal Irish Academy. 
and capitate; coste strong, convergent in the middle, and radiate to- 
wards the ends ; intermediate free space narrow, except in the middle, 
where it is much expanded, reaching to the margin. (Plate 30, 
fie. 31.) 
Kitz. Bac., p. 101, without a figure. This author identifies the 
species with Pinnularia isocephala, Ehr. Kitton, Science Gossip, 
June, 1868, p. 132.—Pinnularia monile, Rab. FI. Eur. Alg., sect. i., 
p- 220, 
Pond near the city of Armagh. Friarstown, Co. Dublin. 
Javicula nodosa, (Ehr.) Fresh water. 
Valve long and narrow; length ‘0024, breadth :0005; margin un- 
dulate, with three nearly equal inflations; costs short, not very close, 
convergent in the middle, radiate towards the ends; intermediate free 
space wide, expanded in the middle. (Plate 30, fig. 26.) 
Kiitz. Bac., p. 101. T. xxviii., fig. 82. This author regards the 
form as identical with Navicula nodosa, Ehr. Infus., 1838, p. 179, T. 
xim., fig. 9. Rab. Siissw. Diat., p. “41, T.vi., fig. 86> Gregory, 
Q.J.M.S., Vol. iv., 1856, p. 3, Pl. 1, fig. 5. Pinnularia nodosa, 
Wnstbm. B.D. Vol. 1.5. p796: | 
Friarstown, Featherbed Mountain, Co. Dublin. River Slaney, 
near Killurin. Camolin, Co. Wexford. Lake near Castlewellan, Co. 
Down. Kilcool, Lugnaquilla Mountain, Co. Wicklow. 
Navicula nodosa, var. staurophora, (Grunow). Fresh water. 
Valve smaller than in the typical species; length 0016, breadth 
‘00025; inflations not so distinct; intermediate free space expanding 
in the middle into a distinct stauroform band reaching the margin. 
(Plate 30, fig. 26 a.) 
Navicula nodosa, Grunow, Verhand, der K. K. Zool. Bot. Gesell., 
Band x., 1860, p. 521, T. ii., fig. 21. 
Navicula bicapitata, (O’Meara). Fresh water. 
Valves small; length ‘0020, breadth -0006; linear, attenuated 
towards the capitate ends; coste fine, convergent at the centre, radiate 
towards the ends; intermediate free space narrow, except at the 
middle, where it is roundly expanded, not reaching the margin. 
(Plate 30, fig. 32.) 
Pinnularia biceps, Gregory, Q.J.M.S., 1856, p. 8, Pl. i, 12. 20. 
Kiutzing has described a form under the name of Navicula biceps, Bac., 
Dp: 96, T. xxvii., fig. 51, which is widely different from the present. 
Gregory’s specific name must therefore be dropped. 
Drumoughty Lough, near Kenmare, Co. Cork. Cawn Lough, 
near Tralee, Co. Kerry. River Bannow, near Clonegal, Co. Carlow. 
Kalcool, Co. Wicklow. Camolin, Co. Wexford. 
