O’Mrara—Report on the Irish Diatomacee. 259 
There is a form resembling the present, described by Ehrenberg as 
Discoplea atmospherica, from Nepal, Mic., T. xxxii. v., fig. 4; and 
also from Fayoom, Egypt, Mic., T. xxxii.i., fig. 83; but as the figures 
of Discoplea atmospherica differ so widely from one another, even if 
there were no doubt as to the identity, a different name is needful to 
mark the peculiarity of the present species. 
Lough Neagh, near Lurgan, Co. Armagh. Lough Mask, near 
Tourmakeady, Co. Mayo. There is a form occurring in the Lough 
Mourne deposit, which may be the same as this, but the papille are 
usually injured, and, judging from the traces that remain, they seem 
to have been more numerous, more slender, and more scattered than in 
the living forms. 
Cyclotella Scotica, (Kiitz.) Marine. 
Valve very small, finely striate on the margin; the centre unstriate. 
Kiitz. 
Gar 00, ... 2» es, and os = Ralis in Priteh., py. SLi, - PI. 
xiv., fig. 17. (Pl. 26, fig. 16.) 
On sea-weeds at the Giants’ Causeway, Co. Antrim. Kiitzing and 
Ralfs describe this species as adnate, but as my specimens had been 
treated with acid before observation, I cannot confirm this character. 
Cyclotella dallasiana, (W. Sm.) Marine. 
Margin of the valve coarsely striate; central part rugose, as if blis- 
tered. Smith represents the central part as “ cellulate ;”’ but Walker- 
Arnott has more accurately described it as ‘‘ puckered, or as if blis- 
tered.”’ 
Wm. Sm., B. D., Vol. i., p. 87. Walker-Arnott, Q. J. M.S, Oct., 
1860, p. 245. Ralfs, in Pritch., p. 818. Rab. Fl. Eur., p. 33. 
Stomachs of Ascidians. Roundstone Bay, Co. Galway. 
Cyclotella punctata, (Wm. Sm.) Fresh water. 
Frustules undulate on front view; on side view, striz close, radiate, 
very finely punctate, puncta smaller towards the margin, which latter 
is surrounded by a circlet of short, fine coste. (Pl. 26; fig. 17.) 
Wm. Sm., B. D., Vol. ii., p. 87. Ralfs, in Pritch., p. 813. Pl. viii., 
fig. 13. Rab. Fl. Eur., p. 33. 
Lough Island-Reavey, Co. Down. Float bog, Co. Westmeath. 
Genus VI. Coscrnopiscus, Ehr. 
Frustules simple, free, lenticular; valve generally uniformly striate. 
trie areolate or moniliform. Without processes or undulations. 
Kiitzing noticed the close affinity between Melosira and the pre- 
sent genus, but in his classification placed them very widely apart, 
