066 Proceedings of the Royal Irish Academy. 
or Novilla; for which reason this species ought to be transferred to a 
new genus, distinguished from Navicula by the cuneate front view 
The side view was sufficiently conformable with Grunow’s description.”’ 
The cuneate appearance of the front view just referred to, I am 
inclined to think, was casual, arising from the separation of the 
valves at one end, while at the other end they retained their 
normal position. In the specimen I was able to observe on the 
front view, there was but a single valve, which did not exhibit any 
tendency to a cuneate outline. 
Stomachs of Ascidians, Roundstone Bay, Arran Islands, Co. Galway. 
Bantry Bay, Co. Cork. 
Navicula griindleriana, N.S. Marine. 
Valve linear elliptical ; somewhat cuneate at the ends ; interme- 
diate free space narrow, except in the middle, where it expands into 
a broad, subquadrangular area. Strie linear, slightly radiate ; fone 
tudinal suleus marginal. (PI. 31, fig. 25.) 
This form strongly resembles a Navicula figured by Schmidt, Atlas, 
T. vi,, figs. 81 and 82; and by this author attributed to Griindler. 
It differs however, inasmuch as the strize in the latter are described 
as punctate; in the present case they are linear. The free area 
around the central nodule in this form is much larger than in that 
figured by Schmidt. The strong similarity has suggested the specific 
name. 
The present form upon first view might be easily confounded with 
Navicula macula, Greg., from which it may be discerned by the 
fact that the ends in the latter are contracted and rounded; in this 
they are cuneate. The striz, too, in this are very much coarser and 
more distant than in Nay. macula. 
Stomachs of Ascidians, Broadhaven Bay, Co. Galway. 
(e) Limose. 
Longitudinal sulci more numerous than in the last, and generally more 
highly developed ; intermediate free space narrow. 
Navicula trieis, (Ehr.) Fresh water. \ 
Valve linear, elliptical, rounded off at the ends. Strie fine, linear, 
parallel ; intermediate free space narrow towards the ends, expanded 
in the middle; length from -0046 to :0072, breadth from ‘0010 
to ‘0016. Longitudinal striz distinct at the margin. (Pl. 31, 
fig. 26. 
ere Bac., p. 92, T. xxviii., fig. 42. Ralfs, in Pritch., p. 907. 
Rab. Fl. Eur. Alg., sect. 1., p. 171. Donkin, N. H. Brit. Diat., 
p. 380, Pl. v., fig. 6.—Navicula firma, Wm. Sm., B. D., Vol.1., p. 48, 
