4 
412 Proceedings of the Royal Irish Academy. 
Pl. vui., fig. 2.—Pinnularia inflexa, Gregory, Q.J.M.S., 1856, 
Transg,, :p.,48, Pl.:v,., fi. 20.. Rab. Flo inn, tile. sect.1 9.08 18. 
The depression of the valve at the ends is marked by a well-defined 
line which renders the species easy of identification. 
Ballysodare, Co. Sligo. Lough Gill, Co. Kerry. Malahide, Co. 
Dublin. 
Nawvicula hungarica, (Grunow). Fresh water. 
Valve small, oblong; elliptical, ends rounded. Striz subdistant, 
strongly costate, radiate; central nodule large; length ‘0009, breadth 
0045. (Plate 34, fig. 19.) 
Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., 1860, 
p. 539, T. i1., fig. 80. Schumann, Diat. der Hohen Tatra, p.76. Rab. 
Hl. Eur. Alg., sect: 1., p. 190. 
Lough Gill, Co. Kerry. Ditch near town of Sligo. Lough Mask, 
near Tourmakeady, Co. Mayo. 
Navicula carassius, (Ehr.) Fresh water. 
Valves small, broadly elliptical; ends broadly and shortly pro- 
duced. Strie costate; radiate; length 0007, breadth :0003. (Plate 
34, fig. 20.) 
Kitz. Bac., p. 95, T. xxvii., fig. 67. The description and figure 
represent the valve as unstriate, but the strie are quite obvious. 
Grunow, Verband. der K. K. Zool. Bot. Gesell., Band x., p. 537, 
T. an; He. 81, and. T.- ay, fie. V1. - Rallis, an -Bmtene sa aoe: 
Donkin, .N- H. Brit, Diat.; p20, BI. aie, fe: 7 at ae mere than 
doubtful if the form described by Donkin as Navicula carassius 
belongs to this species. The figure represents the form as very much 
longer, the ends finer and more produced, than is the case in Navicula 
carassius ; the strie too, are described as granular, the strie in Navicula 
carassius are linear. Donkin regards the species as identical with 
Navicula lacustris, Gregory, Q.J.M.S., 1856, p. 6, Pl. 1., fig. 23b., 
but the true Navicula carassius is broadly elliptical, and not linear, 
as the former is represented to be. Schumann, Diat der Hohen 
Tatra, p. 68. . 
Glenchree, Kilcool, Co. Wicklow. Kilcock, Royal Canal, Enfield, 
Co. Kildare: Dundrum, Co. Dublin. Killeshin, Queen’s Co. Caum 
Lough, near Tralee, Arraglen, Co. Kerry. 
Navicula mutica, (Kitz.) Fresh or brackish water. 
Valve small, broadly elliptical. Strize punctate, radiate; length 
0005, breadth :0003. . (Plate 34, fig. 21.) 
Kiitz. Bac., p. 95, T. i., fig. 32, who found the form in rain 
pools mixed with salt water. Grunow, Verhand. der K. K. Zool. 
