4 
408 Proceedings of the Royal Irish Academy. 
and figured by Kiitzing under the name of Navicula acuta, the de- 
tails of which are so indistinct that identification would be impossible, 
but the outline of the valve is such as to make it certain that it is 
distinct from the present form. Kiitz. Bac., p. 93, T. i., fig. 69. 
In a fossil state, it occurs abundantly in the Lough Mourne de- 
posit. Ina living state, I have found it in the following localities : 
River Erne, near Crossdoney, Co, Cavan. Lower Lake, Killarney, 
Caumlough near Tralee, Co. Kerry. River Dodder, Pond in Botanic 
Gardens of Trinity College, Co. Dublin. Kilcool, Co. Wicklow. 
Navicula acutiuscula, (Gregory). Marine. 
Valve narrow, lanceolate, with acute ends. Stric costate, slightly 
radiate throughout; length :0040, breadth -0005. 
Ralfs, in Pritch., p. 906.—Pinnularia acutiuscula, Gregory, Q. J. 
M; S..1856, Trang., p..48, PL y., fie.2). Rab, HE Bur Ale! secr. 1. 
p. 218. 
Stomachs of Ascidians, seacoast, Co. Clare. 
Navicula peregrina, (Ehr.) Marine or brackish water. 
Valves broadly lanceolate, ends obtuse. Strie costate, sub-distant, 
radiate ; length :0046, breadth :0010. (Plate 34, fig. 6.) 
Kiitz. Bac.,; p. 97, T. xxviii., fig. 52. The form was considered 
by Kiitzing to be identical with Pinnularia peregrina of Ehrenberg. 
Ralfs, in Pritch., p. 906. Cleve, Om Svenska och Norska Dhiat., 
p. 225, Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., 
1860, p. 523.—Pinnularia peregrina, Wm. Sm., B. D., Vol. 1., p. 56, 
Pl. xvi; fig: £70... Rab. Fl: Bur, Alg., sect. igps 213. 
Salt ditch near the Town of Wexford, River Slaney, near Killurin, 
Tacumshane, Co. Wexford. Bellarena, mouth of the River Roe, Co. 
Derry. Rostrevor, Co. Down. Breaches near. Newcastle, Co. 
Wicklow. Kilkee, Co. Clare. Lough Gill, Co. Kerry. Howth, Co. 
Dublin. Stomachs of Ascidians, Broadhaven Bay, Co. Galway. A 
small variety of this species occurred from stomachs of Ascidians 
Belfast Lough, Co. Antrim. 
Navicula zosteret’, (Grunow). Marine. 
Valve, large lanceolate with sharp ends. Strie strongly costate, 
sub-distant, radiate ; length -0056, breadth 0002. (Plate 34, fig. 7.) 
Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860, 
p. 528, T. iv., fig. 23. The locality in which this form was found by 
Grunow was the Adriatic Sea, from a depth of from two to four 
fathoms. I know of no other locality in which the species has been 
discovered save that specified below.—Pinnularia zostereti, Rab. FI. 
Eur. Alg., sect. i., p. 218. 
‘tomachs of Ascidians, Broachayen Bay, Co. Galway. 
