298 welwitsch's African freshwater alg^. 



2. Lyngbya C. Ag. (1824). 



1. L. aureo-fulva, sp. n. L, terrestris, strato spongioso mem- 

 branaceo aureo-fulvo vel flavo ; filis dense intricatis, flexuosis ; 

 vaginis firmis, glabris et lamellosis, flavis vel flavo-brunneis ; 

 trichomatibus jerugineis, ad dissepimenta leviter eonstrictis, apici- 

 bus baud attenuatis ; cellnlis quadratis, nonnunquam diametro 

 paullo brevioribns ; protoplasmate delicate granulato. Crass, fil. 

 13-5-14-5 jx; crass, trich. 8-5-9'5 /x. 



Pungo Andongo. Freq. iu liumidis ad dextram flum. Cuanza ex 

 Candumba usque Quisonde ; March 1857. No. 10. "Alga ter- 

 restris, in vivo aureo-fulva vel flavescens, membranis spongiosis 

 latissimis graminuni cjespitibus intertexta, Droseraceis et Erio- 

 caulouaceis solum spongiosum offerens." 



2. L. Martensiana Menegh. Conspect. Ahjul. Ew/an. 12 (1837) ; 

 Gomout in A^m. ScL Nat. 7e serie, Bot. xvi. 145-6, t. 3, f. 17 (1892). 

 Crass, fil. 11-14 /x; crass, trich. 8-10 /x. 



Goluugo Alto. Ad muscos prope fontem magn. ad Ban9a de 

 SobaBango; Sept. 1855. No. 159. 



Loanda. Cum Symploca Muscorum ad terram humidam urbis 

 Loandfe, tempore pluvio ; April 1854. No. 161. 



8. L. ^RUGiNEo-c^RULEA (Kiltz.) Gomout, I. c. 146-7, t. 4, f. 1-3 

 (1892). OscUlaria ariKiineo-caridea Kiitz. Plujc. Geiier. 185 (1843) ; 

 Tab. Phyc. i. (1845-9), 28, t. 39, fig. ix. Crass, fil. 6-7-7-5 /x; 

 crass, trich. 4-8-5*3 /x. 



Pungo Andongo. Inter Porphurosiphonem Notarisii prope Condo ; 

 March 1857. No. 9. 



4. L. VERSICOLOR (Wartm.) Gomont, I.e. 147, t. 4, fig. 4, 5 (1892). 

 Phormidmm versicolor Wartm. (1861). 



Mossfimedes. Ad ripas limosas flum. Bero pr. Cavalleiros ; 

 June 1859. No. 175. 



3. Phormidium Kiitz. (1843). 



1. P. subsolitarium, sp.n. P. filis non in stratum, ad basin 

 affixis, solitariis vel 2-3 associatis, brevibus, leviter curvatis vel 

 subrectis ; vaginis latis, multe hyaliuis et baud facile visis ; tricho- 

 matibus Iffite ferugineis, moniliformibus, vaginam baud complentibus, 

 apicibus non attenuatis ; cellulis ellipticis vel elliptico-oblongis, post 

 division em subglobosis, protoplasmate parietali ; cellula apicali 

 rotundata, calyptra nulla. Crass, fil. 5 /x ; crass, trich. 2 /x. 



Pungo Andongo. In Batrachospermo ijraciUimo ad lapides sub- 

 mersas in rivulo de Tangue ; May 1857. No. 3. 



The moniliform cells and the delicate hyaline sheath place this 

 plant in the genus PhonnUlium, although the plants often occur 

 singly. The elliptic cells and subsolitary habit characterize the 

 species. 



2. P. angustissimum, sp. n. P. strato tenuissimo membrau- 

 aceo pallide terugineo ; filis flexuosis et tortuoso-intricatis ; vaginis 

 muco hyalino agglutinatis ; trichomatibus angustissimis, laete sevn- 

 gineis, ad dissepimenta eonstrictis, apicibus rectis et non capitatis ; 



