306 Proceedings of the Royal Irish Academy. 
Navicula integra, (Wm. 8m.) Fresh water. 
Valve narrow, elliptic, incurved, then angularly expanded towards 
the ends which are narrow and papillate; strix fine, radiate; inter- 
mediate free space narrow, except at the middle, where it is slightly 
expanded. (Plate 30, fig. 43.) 
Ralfs, in Pritch., p. 895, who describes the striz as reaching the 
. median line. Donkin, N. H. Brit. Diat., p. 40, Pl. vi., fig. 8, where 
the character of the striz is correctly delineated.—Pinnularia integra, 
Wan. Sna.; B.D., Vola; pr 96) Rabe 2, ae Ale ec 
p. 220. 
Powerscourt, Co. Wicklow. 
Navicula pachycephala, (Rab.) Fresh water. 
Valve elliptical, with capitate ends; length ‘0022, breadth 0006; 
costz short, convergent; intermediate free space broad, reaching the 
margin in a narrow stauroform band. (Plate 30, fig. 44.) 
Pinnularia pachycephala, Rab. Stissw. Diat., p. 43, T. vi, 
g. 40. 
Featherbed Mountain, Ballybrack, Co. Dublin. 
Navicula subcapitata, (Gregory). Fresh water. 
Valve narrow, linear, with subcapitate ends; cost coarse and 
distant ; intermediate free space relatively wide, linear; length -0015, 
breadth -0002. (Plate 30, fig. 45.) 
Ralfs, in Pritch., p. 902.—Navicula gracillima, var. subcapitata, 
Rab. Fl. Eur. Alg., sect. i., p. 200.—Pinnularia subcapitata, Gregory, 
Qe Jew. S.. 1856; p./9,-Pira,, te 30. | 
Friarstown, Featherbed Mountain, Killakee, Co. Dublin. Glencar, 
Co. Kerry. Lake near Castlewellan, Co. Down. 
Navicula gracillima, (Gregory). Fresh water. 
Valve narrow, linear, with produced slightly capitate ends, length 
"0018, breadth -00025; coste very fine, convergent in the middle, 
slightly radiate towards the ends; intermediate free space narrow, 
except in the middle, where it is roundly expanded. (Plate 30, 
fig. 46.) ; 
Ralfs, in Pritch., p. 902. Rab. Fl. Eur. Alg., sect.1., p. 199. 
Schumann, Diat. der Hohen Tatra, p. 70, T. iv., fig. 49.—Pinnularia 
gracillima, Gregory, Q.J.M.S., 1856, p. 9, Pl.i., fig. 31. Wm.S8m., 
Bap So Volkm..p. 9a. 
Friarstown, Piperstown, Featherbed Mountain, Co. Dublin. Rath- 
drum, Lugnaquilla Mountain, Co. Wicklow. Drumoughty Lough, 
near Kenmare, Co. Cork. Glencar, Co. Kerry. Lake near Castle- 
wellan, Co. Down. 
