236 wklwitsch's afkican freshwater alg.e. 



Very little could be made out from the specimens which were 

 on dried mud, but a rough sketch made by Welwitsch accompanying 

 them was sufficiently characteristic of the genus. 



XIV. — -Palmellace^. 



1. CcELASTRUM Nag. (1849). 



1. C. ROBusTUM Hantzsch in Rabenh. Ah/. Europ. no. 1407; 

 Keinsch in Abhandl. Xaturhist. Gesellsch. Nurnber<i, Bd. 3, H. 2, 88 

 (1866) ; Schmidle in Berichte der Naturfors. GeseUsch. Freib. 79, 

 t. ii. f. 11 (1893). C. vndicum W. B. Turn, in K. Sv. Vet.-Akad. 

 Handl. Bd. 25, no. 5, 161, t. xx. f. 11 (1893). C. coenobiis globosis, 

 e cellulis 8, 16 vel 32 constitutis, cellulis globosis et subdepressis e 

 mutua pressione, confertis ; metnbrana cellularum crassissima ; 

 areolis minutis et subtriangularibus, Dimens. plant, afric. : — Diam. 

 cffiuob. 67 /A ; diam. cell. 15-16 /x ; crass, membr. cell. 2 /x. 



Libongo. Ad margines flum. Lifune : Sept. 1858. No. 204. 



Var. coNFERTUM var. n. Var. coenobiis miuoribus, e cellulis 64 

 constitutis, cellulis hexagono-spha^ricis, duplo-minor quam in forma 

 typica, areolis miuutissimis et indistinctis. Diam. ccenob. 37 /x ; 

 diam. cell. 7-8 /x. 



Libongo. Cum form. typ. No. 204. 



2. SoRASTRUM Kiltz. (1845). 



1. S. spiNULosuBi Nag. Gatt. einz. Ah/. 99, t. v. D (1849). 

 Diam. ccenob. cum spin. circ. 51 /x ; lat. cell. 17 /x. 



Libongo. Ad margines flum. Lifune ; Sept. 1858. No. 204. 



3. Pediastrum Meyen (1829). 



1. P. Tetras (Ehreub.) Ralfs in Ann. Nut. Hist. xiv. 469, t. 12, 

 f. 4 (1844). Mienisteiias Tetras Ehrenb. (1838). Crenob. 4, 1 + 7, 

 5 + 11 ; diam. 12-5-35 /x. 



Huilla. In paludibus exsiccandis ; April 1860. No. 176. Inter 

 Utriculaiiain, Morro de Lopollo ; April 1860. No. 179. 



Libongo. Ad margines flum. Lifune ; Sept. 1858. No. 204. 



4. Ophiocytium Nag. (1849). 



1. 0. MAJUS Nag. Gatt. einz. Alg. 89, t. iv. A, fig. 2 (1849). 

 Diam. 12*5 /x. 



Pungo Andongo. In stagnis prope Anbilla (Condo); Mai*ch 

 1857. No. 177. 



2. 0. PARVULUM (Perty) A. Br, Ahj. Unicell. 55 (1855). Bro- 

 chidiuin parvulum Perty. Diam. 3-5-4 /x. 



Huilla. In uliginosis editioribus prope Humpata, Empalanca 

 et Lopollo ; May 1860. No. 15. 



Pungo Andongo. In stagnis prope Anbilla (Condoj ; March 

 1857. No. 177. 



5. ScENEDESiius Meycn (1829). 



1. S. DENTicuLATUs Lagcrh. in Ofc Kongl. Vet.-Akad, Forhandl, 

 1882, no. 2, 61, t. ii. f. 18-16. 



