O’Mrara—Report on the Irish Diatomacee. 349. 
under the name of Navicula stauroptera, var. parva, Verhand. der 
K. K. Zool. Bot. Gesell., Band x., 1860, p. 517, T. iv., fig. 19. The 
striation in the present form is, however, coarser than in Grunow’s 
figure, the latter also being more robust, for which reasons I hesitate 
to identify the present form with that of Grunow. 
Lough Neagh, near Lurgan, Co. Armagh. Camolin, Co. Wex- 
ford. 
Navicula hemiptera, (Kitz). Fresh water. 
Valve linear, elliptical, with rounded ends; length -0025, breadth 
°0005; strize costate linear, convergent at the middle, and radiate to- 
wards the ends; intermediate free space narrow, somewhat expanded 
in the middle. (Plate 30, fig. 22.) 
Kutz. Bae; 'p. 97;-T. xxx., fig: 11." Ralfs, i Pritch., p.-908; 
Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860, p. 519. 
This author considers the form may be only a variety of Nayicula. 
viridis, which it greatly resembles, except that it is smaller, and the 
striation very much finer. Cleve, Om Svenska och Norska Diat., 
p. 228.—Pinnularia hemiptera, Wm.'Sm., B.D., Vol. u., p. 95. Rab. 
susew., Diabs--p:- “429°. yi:, figs. 17. Do: Fl Bur: | Alg-., ‘sect. 1. 
p. 212. 7 
Lucan, Featherbed Mountain, Friarstown, Co. Dublin. River 
Erne, near Crossdoney, Derrylane Lough, Co. Cavan. Lough Erne, 
Co. Fermanagh. Lough Neagh, near Lurgan. Ulster Canal, near 
Poyntzpass, Co. Armagh. Pool near Glengarriff, Co. Cork. Streamlet, 
Cushendun, Co. Antrim. River Bann, near Coleraine, Co. Derry. 
Sub-peat deposit, Dromore, Co. Down. 
Navicula apiculata, (De Bréb.) Marine. 
Valve linear in the middle, gradually tapering towards the ends, 
which run out into acute short beaks; length :0026, breadth -0008 ; 
coste fine, converging in the middle, radiate towards the ends; inter- 
mediate free space narrower towards the ends, expanded in the middle. 
(Pl. 30, fig. 23.) 
Pinnularia rostellata, Gregory, Diat. of Clyde, p. 488, Pl. ix., fig. 
20, 1857.—Navicula apiculata, De Brébisson Diat. du Littoral de 
Cherbourg, p. 16, Pl.i., fig. 5, 1867. Ralfs, in Pritch., p. 9038. Donkin 
N. H. Brit. Diat., p. 56, Pl. vii, fig. 6. Kiitzing has described 
a form as Nayicula rostellata, which is quite distinct from the present ; 
it is therefore necessary to drop the specific name adopted by Gregory, 
and substitute for it De Brébisson’s name, Navicula apiculata. 
Gregory and De Brebisson describe the strie as reaching the 
median line; Donkin more correctly represents them as falling short 
of it, but does not describe the central expansion of the free inter- 
mediate space. 
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