O’Mrara—Report on the Irish Diatomacee. 417 
Navicula globifera, N. 8. Fresh water. 
Valve narrow, margin slightly constricted; ends constricted and 
broadly capitate. Striz extremely fine, close, convergent; length 
‘0018, breadth -0003. (Plate 34, fig. 32.) 
This form is very similar to that described by Gregory as Pinnu- 
laria globiceps, Q. J. M. S., 1856, p. 10, Pl.i., fig. 34; but differs in 
the following respects: in Gregory’s form the valve is obviously ex- 
panded in the middle; in this it is linear, with the appearance of a 
‘slight constriction in the middle; the strie in this are much finer, and 
reach the median line, instead of leaving a central stauroform free 
band, as is the case with Pinnularia globiceps. 
Camolin, Co. Wexford. 
Navicula rostellifera, (Gregory). Marine or brackish water. 
Valve minute, narrow, linear ; narrowed towards the ends, which are 
apiculate. Strie costate, convergent in the middle; frustule on front 
view constricted in the middle; length of valve .0013, breadth -0003. 
(Plate 34, fig. 33.) 
Pinnularia apiculata, Gregory, Q. J. M.8., 1856, p. 41, Pl. iv., 
fig. 21. This form appears to be the same which Donkin describes as 
Navicula apiculata, De Brébisson, and Pinnularia rostellata, Gregory, 
Diat., of Clyde, p. 488, Pl. ix., fig. 20. See Donkin, N.H. Brit. 
Diat., p. 56, Pl. vii., fig. 6. Gregory himself evidently regarded the 
forms as distinct; and comparison of the two compels me to coincide 
with that eminent observer. Navicula apiculata, De Brébisson, and 
Pinnularia rostellata, Gregory, are obviously identical, and quite 
different from the present, which is much smaller and narrower in 
proportion ; the striz being very strong, and reaching the median line, 
while in this other. they leave a considerable blank space about the 
central nodule; the rostrate ends too in the latter are much produced, 
while in this species they are very short. Gregory’s specific term 
apiculata having been appropriated by De Brébisson, ought to drop, 
and the form so distinctly described by Gregory bear another desig- 
nation, to avoid confusion. 
Lough Gill, Co. Kerry. Portmarnock, Co. Dublin. 
Navicula cancellata, (Donkin). Marine. 
Valve large, narrow, linear, with cuneate ends. Strie strongly 
costate; convergent in the middle, nearly parallel towards the ends ; 
length ‘0036, breadth -0006. Frustule on front view slightly con- 
stricted, the coste appearing in a broad band. (Plate 34, fig. 34.) 
Donkin, N. H. Brit. Diat., p. 55, Pl. vii. fig. 4. Navicula trun- 
cata, Donkin, Q. J. M.S., 1861, p. 9, Pl.i., fig. 4, and changed for 
the present designation, the former name having been anticipated by 
Kiitzing.—Pinnularia truncata, Rab. Fl. Eur. Alg., sect.i., p. 217. 
Arran Islands; Stomachs of Ascidians, Roundstone Bay; Sto- 
machs of Ascidians, Broadhayen Bray, Co. Galway. Malahide, Port- 
marnock, Co. Dublin. 
