12 NAVICULEZ. 
tapering towards the central nodule; unstriated area 
narrow, lunate. 
Hab. Marine. Frith of Clyde, January 1854 (Mr. 
Hennedy) ; Pool Bay (Prof. Smith); Lyme Regis (Mr. 
Capron) ; Glenshira sand and Lamlash Bay Isle of Arran 
(Prof. Gregory). 
Navicula forcipata, Greville. 
Navieula forcipata, Grev. Quart. Micr. Journ. vol. vii. p. 83, pl. vi. figs. 
10 & 11; Ralfs, in Prit. Inf. p. 897; Rabenh. Europ. Diat, 
p. 178. 
Plate IT. fig. 4. 
Frustule small. V. elliptical; striz fine, granular, about 
35 in ‘001”; marginal band broad in the middle, 
gradually tapering towards the extremities, and having 
a bicrescentic inner border ; median band contiguous 
to the median line, and with a convex outer border ; 
unstriated area narrow, incurved at the extremities 
and middle; dry valve brown. 
Hab. Marine. Lamlash Bay Isle of Arran (Dr. Gre- 
ville) ; common on the sandy beach of the coast of North- 
umberland (A. 8. D.) ; near Hull (Mr. Norman). 
. 
Navicula spectabilis, Gregory. 
Navieula spectabilis, Greg. Diat. of the Clyde, p. 9, pl. i. fig. 10; Ralfs, 
in Prit. Inf. p. 898; Rabenh. Europ. Diat. p. 178. 
Plate Il. fig. 5. 
Frustule large. V. broad, elliptical ; striz coarsely granu- 
lar, about 22 in 001"; marginal band with a doubly 
crescentic inucr border, broad in the middle and 
gradually tapering towards the extremities, median 
