364 Proceedings of the Royal Irish Academy. 
Navicula palpebralis, (De Bréb.) Marine. 
Valve broadly elliptical, lanceolate at the ends; strie distinctly 
costate, linear, radiate, marginal; intermediate free space wide, ellip- 
tical-lanceolate ; length -0034, breadth 00138. (PI. 31, fig. 20.) 
Wm. Sm., B. D., Vol.1.5 p. 5007 Supp, Pib-soex ioe? ee ite 
figure represents the strive as minutely punctate; in reality they are 
strongly costate. Ralfs, in Pritch., p. 905. , Grunow, Verhand. der 
K. K. Zool. Bot. Gesell., Band x., 160, p. 536, T. u1., fig. 27. The 
form here described exactly resembles that of Smith, being very small, 
and with minutely punctate strie. Donkin, N. H. Brit. Diat., p. 25, 
fig. 8. This author regards the species as identical with Navicula 
barclayana, Greg. Rab. Fl. Eur. Alg., sect. i., p. 182, who describes 
the striz as distinctly granulate. 
Stomachs of Ascidians, Broadhavyen Bay, Arran Islands, Co. Gal- 
way. : 
Navicula angulosa, (Greg.) Marine. 
Similar to the preceding, but strie finer and closer, and longer, 
convergent in the middle, radiate towards the ends; mtermediate 
free space, instead of being elliptical, is lanceolate ; length 0050, 
breadth -0010. 
Gregory, Q. J. M. S., 1856, p. 42, Pl. v., fig. 8. Ralfs, in Pritch., 
p. 905. Rab. Fl. Eur. Alg., sect.i., p.176. Donkin, N. H. Brit. 
Dini. .p. 20, Pl tm. oe 
River Slaney, Killurin, Tacumshane, Co. Wexford. Breaches, 
near Newcastle, Co. Wicklow. Malahide, Co. Dublin. Arran Islands, 
Co. Galway. 
Navicula semiplena, (Gregory). Marine. 
Valve as in the preceding form, but much narrower, and the in- 
termediate free space not angular in the middle. 
Donkin, N. H. Brit. Diat., p. 26, Pl. iv., fig. 5—Pinnularia an- 
gulosa, var. 8, Gregory, Q. J. M.S., 1856, p. 42, Pl. v., fig. 8*— 
Pinnularia semiplena, Greville, Q. J. M. S., 1859, p. 84, Pl. vi., fig. 12. 
Malahide, Co. Dublin. Fintragh Bay, Co. Donegal. Rostrevor, 
Co. Down. 
Navicula hebes, (Ralfs). Fresh water. 
Valve gibbous in the middle, ends somewhat attenuated, but 
still broad, and rounded. Striz fine, linear, nearly parallel ; interme- 
diate free space wide in middle, lanceolate towards the ends. (PI. 
31, fig. 21.) 
Baltes, in Pritch., p. 896, who regards the species as identical with 
Navicula obtusa, Wm. Sm., B. D., Vol. i., p. 50, Pl. xvi., fig. 140, 
with which I find it impossible to identify it. Donkin, N. H. Brit., 
Diat,,-p, 23, Bla., fro A: 
Marl, Co. Down. Lough Mourne deposit. 
