36 NAVICULEE. 
Navicula punctata, Kiitzing. 
Stauroneis punctata, Kiitz. Bac. p. 106, t. xxi. fig. 9; Sm. Synop. vol. i. 
p. 61, pl. xix. fig. 189; Ralfs, in Prit. Inf. p. 912; Rabenh. 
Europ. Diat. p. 245. 
Stauroptera punctata, Rabenh, Siissw. Diat. p. 50, t. ix. fig. 11. 
Plate V. fig. 12. 
V. elliptical, deeply constricted into produced, capitate 
apices ; striee conspicuous, granular, about 27 in ‘001", 
oblique, reaching to the median line, shortened oppo- 
site to the central nodule, so as to leave a stauronei- 
form, median, blank space. 
This species has been placed in the genus Stauroneis by 
Kiitzing, on account of the peculiar shortening of the 
strie opposite the central nodule ; it is, however, a genuine 
Navicula, belonging to the present group. 
Hab. Fresh water: frequent in clear streams. River 
Coquet Northumberland, April and May (A. 8. D.). 
Navicula Amphisbena, Bory de St. Vincent. 
Navicula Amphisbena, Bory, Encycl. Méthod. 1824; Turp. Dict. cl. 
t. I. 2. figs. 2&9; Ehren. Inf. 1838, p. 178, t. xiii. fig. 7; 
Kiitz. Bac. p. 95, t. iii. figs. 41 & 42; Rabenh. Siissw. Diat. 
p. 40, t. vi. fig. 66, and Europ. Diat. p. 191; Sm. Synop. vol. i. 
p. 51, pl. xvii. fig. 147; Ralfs, in Prit. Inf. p. 899, pl. vii. fig. 72. 
Navicula ventricosa, Ehren. Abhandlg. d. Berl. Ac. 1830, p. 67. ~ 
Frustulia depressa, Kiitz. Synops. p. 21, fig. 27, Alg. ag. dule, Dee. 8, 
1833. 
Plate V. fig. 18. 
V. broad, elliptical, deeply constricted into produced, ro- 
tund, capitate apices; striz fine, close, about 40 in 
001", oblique and slightly curved, reaching to the 
median line near the extremities, gradually shortened 
towards the middle of the valve, so as to leave a 
