NAVICULA CANCELLATA. 55. 
extremities truncate-rotund. V. lanceolate, subacute, 
terminal nodules conspicuous ; striz distinct, oblique, 
connivent, and slightly shortened around the central 
nodule, reaching to the median line, about 25 in 
001". 
Hab. Marine. Glenshira sand; Estuary of the Clyde 
(Prof. Gregory) ; Linemouth, coast of Northumberland, 
abundant (A. S. D.). 
Navicula longa, Gregory. 
Pinnularia longa, Greg. Trans, Micr. Soc. n. s, vol. iv. p. 47, pl. v. fig. 18; 
Rabenh. Europ. Diat. p. 218. 
Navicula longa, Ralfs, in Prit, Inf. p, 906, 
Plate VIIL figs. 3a & 36, 
Frustule much elongated, on M. V, narrow, slightly con- 
stricted in the middle, angles rounded. V. narrow, 
lanceolate, acute; strie distant, coarse and costate, 
about 14 in :001", oblique, reaching to the median 
line and shortened opposite the central nodule. 
Hab, Marine. Glenshira sand, Lamlash Bay, Isle of 
Arran, and Estuary of the Clyde (Prof. Gregory). 
Navicula cancellata, Donkin. 
Navicula truncata, Donk. Quart. Micr. Journ. un. s. vol. i. p. 9, pl. i. fig. 4. 
Pinnularia truncata, Rabenh, Europ. Diat..p. 217. 
Plate VIII. figs. 4a & 46. 
Frustule on M. V. broad, oblong, rectangular, constricted 
in the middle, extremities truncate, angles prominent. 
V. narrow, linear, or linear-lanceolate, extremities 
tapering, acute or subacute; strie reaching to the 
median line, shortened opposite the central nodule, 
transverse and parallel, coarse and costate, from 14 
to 15 in 001". 
G2 
