680 Bacillarie33, Fragilariaeeie, Desmogonium. 



12. Asterionella Frauenfeldii Grun. in Wien. Verhandl. 1863, p. 140, 

 t. 14, f. 18 est Thaiassioihria; Frauenfeldii Grim. 



Genus ad EunoUaceas vergens. 



DESMOGONiUNi Ehr. [1848] in Schomb. Reise p. 539 (Etyrn. desmos 

 fascia et gonu articulus), Rabenh. Fl. Eur. Algar. I, p. 142, Grun. 

 Diat. Ins. Hanka p. 6, De-Toni Osserv. tasson. Bacill. 1890, p. 905. 

 — Frustula SynedrcB linearia, rectangula, per isthmos gelineos 

 crassiusculos in filaraentuni concatenata, valvge rectae leniterve ar- 

 cuata3, operculum thecse linearis apice rotundatse referentes, utro- 

 que margine superiore serie granulorum ornata3, transverse stria- 

 tae; pseudonoduli terminales in utroque valvae apice duo approxi- 

 mati. 



Obs. Genus vix sui juris, aptius cum Synedra conjungendum. 



1. Desmogonlum Rabenhorstianum Grun. Diat. ins. Banka p. 6, t. 1, 2701 

 f. 1, H. L. Sm. Sp. T. n. 129. — Valvis iinearibus, 70-200 ■:= 5-8, 

 leviter EunoHce ad instar arcuatis, apice plus minusve capitulatira 

 inHatis; striis transversis tenuibus, 16-18 in 10 u.., granulis margi- 

 nalibus 8-9 in 10 y.. 



Hab. inter Algas aquae dulcis insulae uBanka)) (Gersten- 

 berger). 



2. Desmogonium? Kuetzingii Rabenh. Fl. Eur. Algar. I, p. 142, Sy 2702 

 nedra rumpens Kuetz. Bacill. p. 69, t. 16, f. VI, 4 et 5. — Afli- 

 xum, in tabulam conjunctum, deraura solutura, valvis angustissime 

 linearibus, 25-40 a. longis, apicibus tumidulis obtusis. 



Hab. in locis paludosis submarinis Germaniae borealis et insu- 

 Ire «Bornhoim, Waiigerooge » (Kuetzing, Rabenhorst). 



3. Desmogonium gujanense Ehr. in Schorab. Reise 1848, p. 539, Mi- 970.3 

 krogeol. t. 34, 5, A, f. 3, t. 39, 3, f. 23-24, t. 38 A, 13, f. 4, V. 



H. T. n. 273, Pritch. Inf. p. 790, t. XV, f. 13. — Frustulis non 

 stipitatis, valvis sulculis longitudinalibus destitutis, ceterum generis. 

 Hab. in Asia, Africa et America (Ehrenberg). 



Species tantura nomine notae vel inquirendae. 



4. Desmogonium gracile Eulenst. in H. L. Sra. Sp. T. n. 150. ^im 



5. Desmogonium mirabile Eulenst. in H. L. Sm. Sp. T. n. 151 (an 2705 

 AclinellcG sp. 1) 



