ral 
Stauroptera achnanthes, Rabenh., Sussw. Diats., p. 49., t. IX., fig. 2. 
Stauronets achnanthes, Kutz., Bacill., p. 106, t. XXIX., figs. 20 and 22;. Ralfs 
in Prit. Infus., p. 913. 
Stauroneis pulchella, Sm., Syn., Vol. 1., p. 61, pl. XIX., fig. 194.;°Ralfs in 
Prit. Infus., p. 914., pl. VIIL., fig. 77; Donkin, p. 62., pl. X., figs. Ia Ib and Ic. 
Valve elliptical-lanceolate with obtuse extremities; stria 
oblique and granular, forming a stauros at the central nodule. 
Hab.—Marine, not frequent. South Beach, Clifton and Prince’s 
Bay. (Fig. 6.) 
NAVICULA BINODIS, Ehr. 
Navicula binodis, Ralfs in Prit. Infus., 1861, p. 893; Rab nh., Sussw. Diats., p._ 
41, t. V., fig. 5; Sm., Syn., Vol. I., p. 53, pl. XVIL., fig. 159; Kutz., Bacill., p. 100, 
t. IIL. fig. 35; Donkin, p. 38, pl. VI., fig. 3; Van Heurck, Suppl., pl. B., fig. 33. 
Valve oblong, constricted opposite the central nodule, and 
terminating in produced, narrow extremities ; striz indistinct. 
Hab.—Fresh water, frequent, not abundant. In ponds, Clifton, 
New Brighton. (Fig. 7.) 
NAVICULA DICEPHALA, Kiitz. 
Navicula dicephala, Kutz., Bacill., p. 96, pl. 28, fig. 60, 62c.; Sm., Syn., p. 53, 
pl. XVIL., f. 157; Brun, Diat., p. 76., pl. VIL, fig. 34; Van Heurck, pl. VIII., figs. 
33, 34- 
Pinnularia dicephala, Ehr. 
Valve linear, constricted toward the rounded extremities ; 
strie transverse, granular; large central nodule more or less 
square; median line often double. 
Hab.—F resh water, frequent. In ponds, Clifton, New Brighton 
and Garretsons. (Fig. 8.) 
NAVICULA DIDYMA, Ehr. 
Navicula didyma, Katz., Bacill., p. 100, t. IV., fig. 7., t. XXVIIL, fig. 75; 
Ralfs in Prit., Infus., pl. XV., fig. 12; Donkin, p. _ pl. VIL., figs. 8a and 8b.; 
Sm., Syn., Vol 1., p. 53; Van Heurck, pl. IX.,figs. 5, 6 
Pisnalevis didlos, Rabenh., Sussw. Diats., p. 46, pl. VL., fig. 26. 
Diploneis didyma, Ehr. 
Valve more or less constricted in the centre; extremities 
broadly oval; striz granular, transverse, but toward the extrem- 
ities oblique, less pronounced near the median line. 
Hab.—Marine, frequent. South Beach, Clifton, Prince’s 
Bay and salt meadows at New Dorp. (Fig. 9.) 
/ NAVICULA INFLEXA, Greg. 
Pinnularia inflexa, Rabenh., Eur., Diats., p. 218. 
Navicula inflexa, Raisin Prit, Infus., p. 905; Donkin, p. 54, pl. VIII., figs. 2a 
and 2b, 
