O’Mrara—Report on the Irish Diatomacee. 393 
Brit. Diat., p. 12, Pl. i., fig. 4. And likely the same as that figured 
by Schmidt, Atlas der Diat., T. 11, fig. 36. 
Arran Islands; Stomachs of Ascidians, Roundstone Bay; Sto- 
machs of Ascidians, Broadhaven Bay, Co. Galway. Bannow, Co. 
Wexford. Malahide, Portmarnock, Piles of wooden bridge, Dolly- 
mount strand, Dalkey, Co. Dublin. Rostrevor, Dundrum Bay, Co. 
Down. Lough Gill, Co. Kerry. 
Var. abrupta, (Gregory). Marine. 
Like the last described variety, but the strie are costate, and the 
intermediate lyrate free space does not extend so near the ends. 
Gregory, Diat. of Clyde, p. 486, Pl. ix., fig. 14. Rab. Fl. Eur., 
Alg., sect. -1., p. 178. Donkin, N. H. Brit. Diat., p. 13, Pl. ii., 
fig. 6. Gregory and Donkin figure the species with obscurely moni- 
liform strie ; and therefore I have a doubt of the identity of the pre- 
sent variety with that so described. Supposing the figures referred to 
be exact in this particular, I could scarcely distinguish between the 
former and Navicula lyra, var. elliptica. 
Arran Islands; Stomachs of Ascidians, Roundstone Bay; Sto- 
machs of Ascidians, Broadhaven Bay, Co. Galway. 
Var. costata, (O’Meara). Marine. 
Valve broadly elliptical; marginal band of striz broad; inner band 
of strie narrow; strie distinctly costate, close, parallel in the middle, 
slightly radiate towards the ends, which latter are slightly cuneate ; 
intermediate lyrate space very narrow, convergent at the ends, and 
reaching to the apices; length ‘0024, breadth -0012. 
Arran Islands; Stomachs of Ascidians, Broadhaven Bay; Sto- 
machs of Ascidians, Roundstone Bay, Co. Galway. 
Var. seductilis, (Grundler). Marine. 
Valve narrow, linear-elliptical; marginal band of strie relatively 
wide; inner band of strize narrow; striz very fine, linear, parallel in 
the middle, slightly, radiate towards the ends, lyrate smooth space 
very narrow; length about ‘0020, breadth about :0006.—Navicula 
seductilis (Griindl), Schmidt, Atlas der Diat., T. u., fig. 35. 
Yokohama. (Plate 33, fig. 5.) 
Stomachs of Ascidians, Roundstone Bay, Co. Galway. 
Var. constricta, (O’Meara). Marine. 
Valve linear, elliptical, slightly constricted in the middle, ends 
cuneate, rounded at the extremity; strie, fine, moniliform, lyrate; 
free space narrow, converging at the ends; length ‘0042, greatest 
breadth -0016, breadth in the middle -0015. (Plate 33, fig. 6.) 
Stomachs of Ascidians, Broadhaven Bay, Co. Galway. 
