356 Proceedings of the Royal Irish Academy. 



Navicula Integra, ("Wm. Sm.) Presh. "water. 



Valve narrow, elliptic, incurved, then angularly expanded towarda 

 tlie ends which are narrow and papillate ; striae fine, radiate ; inter- 

 mediate free space narrow, except at the middle, where it is sKghtly^ 

 expanded. (Plate 30, fig. 43.) 



Ealfs, in Priteh., p. 895, who describes the striae as reaching tha 

 median line. Donkin, JS". H. Brit. Diat., p. 40, PI. vi., fig. 8, where 

 the character of the striae is correctly delineated. — Pinnularia Integra^ 

 Wm. Sm., B. D., Vol. ii., p. 96. Eah. M. Eur. Alg., sect, i, 

 p. 220. 



Powerscourt, Co. "Wicklow. 



Navicxda imchycefTiala, (Rah.) Freshwater. 



Valve elliptical, with capitate ends ; length "0022, breadth '0006 ; 

 costse short, convergent ; intermediate free space broad, reaching the 

 margin in a narrow stauroform band. (Plate 30, fig. 44.) 



Pinnularia pachycephala, E,ab. Siissw. Diat., p. 43, T. vi., 

 fig. 40. 



Featherbed Mountain, Ballybrack, Co. Dublin. 



Navicula subcapitata, (Gregory). Presh water. 



Valve narrow, linear, with subcapitate ends ; costse coarse and 

 distant; intermediate free space relatively wide, linear; length "OOIS^ 

 breadth -0002. (Plate 30, fig. 45.) 



Ealfs, in Priteh., p. 902. — iN'avicula gracillima, var. subcapitata^ 

 Eab. PL Eur. Alg., sect, i., p. 200. — Pinnularia subcapitata, Gregory^ 

 Q. J. M. S., 1856, p. 9, PI. i., fig. 30. 



Priarstown, Peatherbed Mountain, Killakee, Co. Dublin. Glencar^ 

 Co. Kerry. Lake near Castlewellan, Co. Down. 



Navicula gracillima, (Gregory). Presh water. 



Valve narrow, linear, with produced slightly capitate ends, length. 

 "0018, breadth "00025; costcS 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 Priteh., p. 902. Eab. PI. Eur. Alg., sect, i., p. 199. 

 Schumann, Diat. der Hohen Tatra, p. 70, T. iv., fig. 49. — Pinnularia 

 gracillima, Gregory, Q. J. M. S., 1856, p. 9, PI. i., fig. 31. Wm. Sm.,. 

 B.D., Vol. ii., p. 95. 



Priarstown, Piperstown, Peatherbed Mountain, Co. Dublin. Eath- 

 di'um, Lugnaquilla Mountain, Co. Wicklow. Drumoughty Lough, 

 near Kenmare, Co. Cork. Glencar, Co. Kerry. Lake near Castle- 

 wellan, Co. Down. 



