‘40 NAVICULE#. 
B. Extremities linear or mucronate. 
Navicula Rostellum, Smith. 
Navicula Rostellum, Sm. Synop. vol. ii. p. 93; Ralfs, in Prit. Inf. p. 900; 
Rabenh. Europ. Diat. p. 195. 
Navicula apiculata, Greg. Quart. Micr. Journ. vol. iv. p. 4, pl. i. fig. 18, 
Plate VI. fig. 7. 
Frustule small. V. broadly elliptical-lanceolate, suddenly 
constricted into produced, linear, short, obtuse apices ; 
strive indistinct, 80 in ‘001". . 
Hab. Fresh water. Grasmere, Aug. 1853 (Prof. Smith) ; 
Falls of Tummel, July 1854 (Dr. Greville) ; Mull earth, 
Elgin, &c. (Prof. Gregory). 
Navicula integra, Smith. 
Pinnularia integra, Sm. Synop. vol. ii. p. 96; Rabenh. Europ. Diat. 
p. 220. 
Pinnularia rostrata, Greg. Quart. Micr. Journ. vol. iv. p. 4, pl. i. fig. 14, 
Navicula integra, Ralfs, in Prit. Inf. p. 895. 
Plate VI. fig. 8. 
Frustule minute. V. elliptical-lanceolate, slightly inflated 
in the middle and suddenly constricted into produced, 
mucronate apices; striz fine, indistinct, reaching to 
the median line, stouter and more distant around the 
central nodule. 
Hab. Fresh water. Powmouth Ayrshire (Prof. W. 
Arnott) ; various localities in Scotland (Prof. Gregory) ; 
River Coquet Northumberland (A. 8. D.). 
