O’Mrara—Report on the Irish Diatomacee. 355 
Bot. Gesell., Band. x., 1860, p. 518, T. iv., fig. 15, which represents the 
coste as stronger and more distant than they are in my specimens. 
—Stauroneis scalaris, Kiitz. Bac., p. 106, 1. xxix., fig. 37. In this 
figure the form is wider than in my specimens, and the stauroform band 
is much narrower than in Grunow’s figure, as well as in my specimens. 
—Stauroptera scalaris, Ehr., Rab. Siissw. Diat., p. 49, T.ix., fig. 8. 
Camolin, Co. Wexford. 
Navicula cuneata, N.S. Fresh water. 
Valve linear, cuneate at the ends. Length .0025, breadth -0006. 
Cost strong, convergent in the middle, radiate towards the ends; 
intermediate free space broad, expanded in the middle. (Pl. 30, 
fig. 40. 
= form in outline much resembles Pinnularia acuminata, Wm. 
Sm., B. D., Vol. i., p. 55, Pl. xviii., fig. 164, but differs from it 
in the following details :—In the latter the strie are coarser, shorter, 
and parallel, the intermediate free space is much wider than in this, 
and haying no expansion such as is very obvious in the present form. 
Featherbed Bog, Co. Dublin. 
Navicula acuminata, (Wm. 8m.) Fresh water. 
Valve linear, ends cuneate. Length 0029, breadth -0006. Coste 
coarse, nearly parallel in the middle, and slightly radiate towards the 
ends; intermediate free space wide. (PI. 30, fig. 41.) 
Ralfs, in Pritch., p. 909.—Pinnularia acuminata, Wm. Sm., B. 
De Vo. i, p.-a0, 61. xvi, ue, 16%, “Rap. “9, ur. Ale. ‘sect. 1,, 
p.- 216. 
Featherbed Mountain, Killakee, Co. Dublin. Kilcool, Co. Wick- 
low. Rostrevor, Co. Down. 
Navicula retusa, (De Brébisson). Marine. 
Valve narrow, oblong, rounded at the ends; striz course, distant, 
nearly parallel ; intermediate free space relatively wide; length :0026, 
breadth :0004; frustule on front view constricted; angles much 
rounded. (Plate 30, fig. 42.) 
De Bréb., Note sur Diat. de littoral de Cherbourg., p. 16, fig. 6. 
Ralfs, in Pritch., p. 908. Donkin, Q.J.M.S., 1857, p. 14, Pl. i., fig. 
17. Do. N. H. Brit. Diat., p. 64, Pl. x., fig. 3. Rab. Fl. Eur. Alg., 
sect. 1., p. 186. Donkin agrees with Walker Arnott in regarding this 
form as identical with Navicula pectinalis, Wm. Sm., B. D., Vol. ii., 
p-. 91, 
Malahide, Co. Dublin. Arran Islands, Stomachs of Ascidians, 
Roundstone Bay, Co. Galway. 
