8 NAVICULER. 
Pinnularia oides, Rabenh. Stissw. Diat. p. 43, t. vi. fig. 18. 
Cocconets striata, Ehren, Mikrogeo. t. XV. B. fig. 16? 
Cocconets finnica, Ehren. Mikrogeo. t. XVII. ii. fig. 19? 
Plate I. figs. 6a & 68. 
V. oval, or elliptical, or oblong-elliptical ; strize 27 in 001", 
distinct, connivent, granular, and crossed by a longi- 
tudinal incurved line, with a bulging-out opposite the 
central nodule. Variable in size and outline. 
Hab. Fresh and brackish water, common. This is one 
of the few species thriving in either fresh or moderately 
brackish water; in the latter localities I have found some 
of the finest specimens. 
Navicula nitescens, Gregory. 
Navicula Smithii, var. ntescens, Greg. Diat. of the Clyde, p. 15, pl. i. 
fig. 16. 
Navicula nitescens,. Ralfs, in Prit, Inf. p. 898; Rabenh. Europ. Diat. 
p. 179. 
Pinnularta Arraniensis, O'Meara, Quart. Mier. Journ. vol. vii. n. s. 
p- 116, pl. v. fig. 6. 
Plate I. fig. 7. 
V. elliptical, attenuated towards the extremities; striae 
coarse, obscurely granular, about 16 in -001", conver- 
ging towards the centre, and divided into two nearly 
equal sections by a longitudinal incurved line parallel 
with the margin. 
Hab. Marine. Lamlash Bay Isle of Arran, and Loch 
Fyne (Prof. Gregory); stomach of Ascidians near Hull 
(Mr. Norman). 
Navicula lineata, Donkin. 
Navicula pao Donk. Trans. Micr. Soc. n. s. vol. vi. p. 82, pl. ili. 
g. 
Plate I. fig. 8. 
V. lincar-clliptical, with a gentle constriction in the middle ; 
