O’Mrara—Report on the Irish Diatomacee. 413 
Bot. Gesell., Band x., p. 538, T. v., fig. 16, who found the species in 
fresh water as well as in brackish. Ralfs, in Pritch., p. 905. Schu- 
mann, Diat. der Hohen Tatra, p. 69. Rab, Fl. Eur. Alg., sect. i., 
p- 185. It is not improbable that this species is identical with the 
form described by Gregory as Navicula lepida, var.  B, ? Q.J.M.S., 
£500, °);.),.01.1., he. 25; B: 
Bannow, Co. Wexford. Lough Gill, Co. Kerry. In these, fresh 
water forms and marine were mingled. Glenchree, Killakee, Co. 
Dublin. Lough Mask, near Tourmakeady, Co. Mayo. The three last- 
named localities were ‘wholly free from marine influences. Hence I 
consider that though the form has been found in brackish water, it is 
essentially a fresh water species. 
Navicula semen, (Ehr.) Fresh water. 
Valve linear, elliptical, broad; ends broadly and shortly produced. 
Strize costate; convergent in middle, radiate towards ends; length 
‘0018, breadth :0008. (Plate 34, fig. 22.) 
Kitz. Bac., p. 99, T. xxvii, fig. 49, who attributes the species 
to Ehrenberg. Wm.Sm., B. D., Vol.i., p. 50, Pl. xvi., fig. 141. Hei- 
berg, De Danske Diat., p. 82. Ralfs, in Pritch., p. 900. Donkin, 
N. H, Brit. Diat., p. 21. Pl. 11., fig. 8. Schumann, Diat. der Hohen 
Tatra, p. 68. 
Stream, Bellarena, Co. Derry. Lough Mourne deposit, Co. Antrim, 
Navicula humilis, (Donkin). Fresh water. 
Valve small, inflated in the middle, with broad capitate ends. Striz 
costate, coarse, subdistant, radiate; central nodule large; length 0010, 
breadth -0008. On front view, frustule quadrangular, slightly con- 
stricted in the middle; costz divergent, leaving a considerable space 
about the central nodule, which latter appears very highly developed. 
Donkin, N. H. Brit. Diat., p. 67, Pl. x., fig. 7. Donkin considers 
this form identical with Nayicula inflata, var. Gregory, Q. J. M. &., 
1855, Pl. ii., fig. 20 c. 
Lough Gill, Co. Kerry. Lough Mask, near Tourmakeady, Co, 
Mayo. 
Navicula inflata, (Kitz.) Fresh water. 
Valve small, inflated in the middle; ends narrowed, produced, 
and scarcely capitate. Striz closely granular, radiate; length -0010, 
breadth ‘00035. (Plate 34, fig. 23.) 
Kiitz. Bac., p. 99, T. iu, fig. 36. Wm.Sm., B.D., Vol. 1. p. 50, 
Pl. xvu., fig. 158. Grunow, Verhand. der K. K. Zool. Bot. Gesell., 
Band x., 1860, p. 538, T. iy., fig. 41. Ralfs, in Pritch., p. 899. Hei- 
