NAVICULA SERIANS 4) 
Subsection VI. Valve lanceolate ; strie fine, transverse, or slightly 
oblique, reaching to the median line. 
Navicula fulva, Nitzsch. 
Frustulia fulva, Nitzsch (ex parte), Breitage, p. 87, t. iii. fig. 19 (1817). 
Navicula fulua, Ehren. Inf. 1838, p. 177, t. xiii. fig. 6, Mikrogeo. numer. 
figs.; Rabenh. Siissw. Diat. p. 37, t. v. fig. 17, and t. vi. fig. 62. 
Navicula cuspidata, Kiitz. Bac. p. 94; Ralfs, in Prit. Inf. p. 905. var. 
Rabenh. Europ. Diat. p. 170, 
Plate VI. fig. 9. 
V. lanceolate, slightly constricted beneath the obtuse 
extremities ; striz slightly oblique, fine, about 30 in 
001". 
After a very careful comparison of this form with 
N. cuspidata, Kiitz., which it closely resembles in general 
outline, I have considered it necessary to reestablish it as 
a species by separating it from the latter, from which it 
differs essentially in its smaller, narrower, and yellowish- 
brown-coloured valve, with unproduced extremities, coarser 
and distinctly oblique striz. 
Hab. Fresh water in subalpine localities. Loch-Oich 
deposit (A. S. D.). 
Navicula serians, De Brébisson. 
Navicula serians, Bréb. in Kiitz. Bac. p. 92, t. xxx. fig. 28; Rabenh. 
Siissw. Diat. p. 38, t. vi. fig. 51, and Europ. Diat. p. 172; 
Sm. Synop. vol. i. p. 47, pl. xvi. fig. 180; Ralfs, in Prit. Inf. 
. 904. 
Navicula a Ehren, Amer. 1848, t. I. iii. fig. 4, t. IL. vi. fig. 27, 
and t. IV. i. fig. 6, and Mikrogeo. numer. figs. 
Navicula punctulata, Ehren. Mikrogeo. t. XVI. i. fig. 1. 
Plate VI. fig. 10. 
V. rhomboid-lanceolate, with subacute extremities ; striz 
E 
