— 908 — 
Conspectus generum 
ï. Aquae dulcis incolae (vel fossiles). 
A) Dissepimenta parietalia lantum 2 in unoquoqiie fruslulo (Gfr. 
Tabellariam fenestratam). 
Diatomella Grev. — Dissepimenta ter perforata. Valvae nodulo 
mediano subdistincto saepius instructae ; costae nuUae. 
B) Dissepimenta parietalia plura in unoquoque frustulo (Gfr. 
Tahellarla Ehrenb. — Frustula catenas soliitas efformantia. Gostae 
nuUae. 
GompJiogramma A. Br. — Frustula solitaria vel geminata ; disse- 
pimenta interrupta clavata ; valvae costis perviis instructae. 
Tetracyclus Ralfs. — Frustula plerumque in fascias plus minus 
longa conjuncta ; valvae subcruciformes costis perviis instructae, 
nodulis nullis. 
StyloUhlium. — Frustula cylindrica ; valvae orbiculares, costatae 
(Genus fossile). 
11. Genera marina. 
A) Dissepimenta parietalia lantum duo in unoquoque frustulo. 
Grammatophora Ehr. — Dissepimenta varie undulata, medio per- 
forata. Valvae striato-punctatae, ecostatae (Frustula rectangula 
catenas solutas efformantia). 
? Climaconeis Grun. — Dissepimenta scalaeformia ; valvae striato- 
punctatae, ecostatae (Frustula bacillaria, libera ?). 
B) Dissepimenta parietalia plura in unoquoque fruslulo. 
t Valvae costatae et striato-punctatae. 
Rhahdonema Kuetz. — Dissepimenta plana, circuito celluioso pun- 
clata ; valvae subcostatae, inler costas punctato-strialae (Frustula 
rectangula in fascias longiores slipilatas conjuncta). 
? Climacosira Grun. — Disse[iimenta numerosa, irregulariter scali- 
formia ; valvae lineares, costatae (?) (Frustula tabulala, rectan- 
gula in fascias conjuncta). 
tt Valvae ecostatae. 
Hyalosira Kuetz. — Frustula Tabellariae, in catenas brèves so- 
lutas stipitatas conjuncta ; valvae lanceolatae (nec nodulosac). 
Striatella Ag. — Dissepimenta annuliformia, plana, haud interrupta; 
valvae lanceolatae striato-punctatae, ecostatae (Frustula tabulata 
rectangula* in fascias stipitatas conjuncta). 
