SURIRELLA AMPHIOXYS WM. SM.
Valve oblong-linear, with cuneate ends; pseudoraphe narrow; costæ, 3-4 in 10 µ; striæ, 14-16 in 10 µ, somewhat radiate. L. 34-54 µ.
Surirella mœlleriana Grun.
Fresh and brackish water. Common along the coast.
Pl. [35], Figs. 12 and 13.
SURIRELLA ROBUSTA EHR.
Valve linear-ovate; pseudoraphe wide; alæ prominent; costæ wide, 1¼ in 10 µ. Frustule in zone view clavate. L. 200-365 µ.
Fresh water.
Pl. [36], Fig. 2.
SURIRELLA SPLENDIDA (EHR.) KUETZ.