O’Mrara—Report on the Irish Diatomacee. 415 
Pl. xvii., fig. 155, Ralfs, in Pritch., p. 901; Cleve, Om Svenska och 
Norska Diat., p. 228. Donkin, N. H. Brit. Diat,, p..37, Pl. v., fig. 14. 
Schumann, Diat. der Hohen Tatra, p. 68. 
Tacumshane, Co. Wexford. Bowen’s Court, Co. Cork. Lough 
Gill, Co. Kerry. Lough Mask, near Tourmakeady, Co. Mayo. Dysart, 
Co. Waterford. 
Navicula angustata, (Wm. Smith). Fresh water. 
Valve very narrow, elliptical; ends produced and slightly capitate. 
Striz fine, linear, radiate; length :0016, breadth :0003. (Plate 34, 
fig. 26.) 
Wine BoD Vol. ae. pi, o2, Pl. xvi, ie. 56. Ralis; im 
Pritch., p. 901. Castracane, Cataloga di Diat. raccolte nella Val. In- 
trasca, p. 12. Schumann, Diat. der Hohen Tatra, p. 68.—Navicula 
cryptocephala, var. rhyncocephala, Grunow, Verhand. der K. K. Zool. 
Bot. Gesell., Band x., 1860, p. 527, T. iv., fig. 280. 
Bantry, Co. Cork. Black Castle, Co. Wicklow. Malahide, Co. 
Dublin. Lough Mask, near Tourmakeady, Co. Mayo. 
Navicula lagerstedtii, N.S. Fresh water. 
Valve small, rhombic; ends slightly produced. Striz obviously 
punctate, radiate, sub-distant; when the centre is not exactly in 
focus, there is the appearance of a narrow stauroform band, which dis- 
appears when properly focused; length :0010, breadth 0005. (Plate 
34, fig. 27.) 
Lough Mask, near Tourmakeady, Co. Mayo. Lough Gill, Co. 
Kerry. In the latter, marine and fresh water species were mingled, 
but in the former locality marine influence was impossible; the form 
is therefore to be regarded as inhabiting fresh water. 
Navicula gastrum, (Ehr). Fresh water. 
Valve rhombic; ends scarcely produced. Stri linear, convergent 
in the middle, radiate towards the ends; length ‘0018, breadth -0009. 
(Plate 34, fig. 28.) 
Kiitz. Bac., p. 94, T. xxvii, fig. 56, who regards the species as 
identical with Pinnularia gastrum, Ehrenberg.  Ralfs, in Pritch., 
p: 900. Donkin, N.H. Brit: Diat.,.p..22) Pl. in., fig.10. This figure 
represents the form as much narrower, and the ends more produced 
than is the case in my specimens.—Pinnularia gastrum, Rab. Siissw. 
Diat., p. 44, T. vi., fig. 15. This last figure represents the stric as 
parallel, which is not accurate. Gregory, Q. J. M.S., 1855, p. 41. 
Plate iv., fig..20. 
Dundalk, Co. Louth. Lough Gill, Co. Kerry. Lough Mask, near 
Tourmakeady, Co. Mayo. Lough Mourne deposit. 
