PLANCHE V

Figure 1.

Figure 2.

Figure 3.

Figvre 4.

Figure 5.

Figure 6.

Cocconeïs splendida .

Rhoïconeïs trinodis . Grun.

a, Valve supérieure;

Valve inférieure;

c, Groupe de deux frustules

Gephyria media , Arnott.

Face connective;

b , Face valvaire.

Navicula subsalina.

Navicula sphœrophora.

Amphiprora pulchra, Bailey.

Face valvaire.