NAVICULA PALPEBRALIS. 25 
Navicula maculosa, Donkin, n. sp. 
Plate V. fig. 1. 
Frustule small. V. linear-elliptical, constricted into pro- 
duced, narrow, tapering, obtuse or subacute apices; 
striz somewhat coarse, distinctly granular, oblique, 
connivent, reaching to the median line, but shortened. 
around the central nodule; dry valve of leaden-blue 
colour. 
This species, in outline, resembles N. apiculata, Bréb., 
but is essentially different in the flatness of its valve and 
in the character of its striw, the granules of which are 
large and distinctly segregated, like those of N. granulata, 
Bréb., to which it is allied. 
Hab. Marine; generally associated with N. humerosa, 
Bréb. Linemouth, Northumberland; coast of Jersey 
(4. 8. D,). 
Subsection III. Valve oblong-elliptical, or elliptical-lanceolate ; 
extremities rounded or acute; strice uninterrupted, not reach- 
ing to the median line. 
Navicula palpebralis, De Brébisson. 
Navicula palpebralis, Bréb. in Sm, Synop. vol. i. p. 50, pl. xxxi. fig. 273; 
Ralfs, in Prit. Inf. fig. 905; Rabenh. Europ. Diat. p. 182. 
Navicula Barclayana, Greg. Diat. of the Clyde, p. 8, pl. 1. fig. 9; Ralfs, 
in Prit. Inf. p. 903; Rabenh. Europ. Diat. p. 201. 
Plate IV. figs. 3a & 36. 
V. elliptical-lanceolate, extremities acute and slightly mu- 
cronate ; strie marginal and of nearly equal length 
(leaving an elliptical, or elliptical-lanceolate, median 
blank space), oblique, subparallel, costate, about 22 
in 001". 
