NAVICULA LATA. 71 
Pinnularia gibba, Sm. Synop. vol. i. p. 58, pl. xix. fig. 180 ? 
Pinndaria Tabellaria, Sm. Synop. vol. i. p. 58, pl. xix. fig. 181 P 
Plate XII. fig. 3. 
Frustule of median size, elongated. V. narrowish, linear, 
bulging in the middle and at the rounded extremities : 
striz not reaching to the median line, much shortened 
and often interrupted on one side of the central 
nodule, very oblique, subdistant, stout and costate, 23 
in 001". 
Hab. Fresh water, frequent in boggy pools in elevated 
and hilly districts. Loch-Oich deposit, Lough-Mourne 
deposit, Premnay Peat, &c. 
Navicula lata, De Brébisson. 
Navicula lata, Bréb. Considér. sur les Diatom. 18388, p. 18; Kiitz. Sp. 
Alg. p. 79; Ralfs, in Prit. Inf. p. 908. 
Pinndaria lata, 8m. Synop. vol. i. p. 55, pl. xviii. fig. 167; Rabenh. 
Europ. Diat. p. 212, and Siissw. Diat. p. 42. 
Pinnularia pachyptera, Ehren. Amer. 1844, p. 183, t. IV. ii. fig. 9; 
Rabenh. Siissw. Diat. p. 45, t. vi. fig. 11. 
Navicula pachyptera, Kiitz. Bac. p. 98, t. xxviii. fig. 58; Ralfs, in Prit. 
Inf. p. 896. 
Pinnularia megaloptera, Ehren. Mikrogeo. t. IIL. i. fig. 4; Greg. Quart. 
Micr. Journ. vol. iv. p. 3, pl. i. fig. 6. 
Navicula Suecica, Ehren. Inf. 1888, p. 189, t. xxi. fig. 18; Kiitz. Bac, 
p- 96, t. xxi. fig. 16; Ralfs, in Prit. Inf. p. 908. 
Pinnularvia Suecica, Ehren, Mikrogeo. ; Rabenh. Siissw. Diat. p. 42, t. vi. 
fig. 14. 
Plate XIII. figs. la & 18. 
Frustule short, oblong. V. broad linear, slightly dilated 
in the middle, and broadly rounded at the extremities 
(in short specimens elliptical or linear-elliptical) ; strize 
not reaching to the median line, much shortened and 
connivent around the central nodule, distant, broad 
and costate, 8 in ‘O01". 
This species is very variable in size and outline, the 
H2 
