WELWITSCH's AFRICAN FRESHWATER ALG^E. 299 



cellulis diametro 2-8-plo (plerumque 4-5-plo) longioribus, proto- 

 plasmate homogeueo. Crass, trich. 0*6-0*8 /x. 



Mossjimedes. Inter GUwtricJdam cFthiopiciva et Charam sp. in 

 rivo Cavoca prope Cabo Negro ; Sept. 1859. No. 19. 



Pungo Andongo. luter Nostoc repandum ad rupes editiores 

 vulcan. prope Caboudo tempore pluvio ; Febr. 1857. No. 21. 



This narrow species is nearest to P. laminosum (Ag.) Gomont, 

 but it is distinguished by its much narrower trichomes, which are 

 constricted at the dissepiments, and its usually much longer cells. 



3. P. LAMINOSUM (Ag.) Gomont in Jouni. de Botaniq. iv. 355 

 (1890) ; in Ann. Sci. Nat. 7e serie, Bot. xvi. 167-8, t. 4, f. 21, 22 

 (1892). Oscillatuna laminosa Ag. in Flora, x. G33 (1827). Crass, 

 lil. 1-5 iJ.. 



Golungo Alto. Ad terram limosam post pluvias ; Dec. 1855. 

 No. 166. 



4. P. CoRiUM (Ag.) Gomont in Juuni. de Botaniq. iv. 355 (1890) ; 

 in Ann. Sci. Nat. I. c. 172-3, t. 5, f. 1, 2 (1892). Oscillatoria Corixim 

 Ag. Dispos. AUjar. Suec. 36 (1812). Crass, fil. 3-4-4'4 /x. 



Sierra Leone. Cum Oscillatoria animali ad parietes humid, 

 verticales urbis Freetown freq. latissimis plagis atro-nitentibus 

 parietes obducens ; Sept. 1853. No. 167. 



5. P. PAPYRACEUM (Ag.) Gomout in Journ. de Botaniq. iv. 355 

 (1890) ; in Ann. Sci. Nat. I. c. 173-5, t. 5, f. 3, 4 (1892). Lhcillatoria 

 jjapijracea Ag. Syst. Ahjar. 61 (1824). 



Sierra Leone. Ad muscos (hepaticeas) humidos in domicil. 

 parietibus verticalibus urbis Freetown frequens tempore pluvio ; 

 Sept. 1853. No. 174. 



6. P. Retzii (Ag.) Gomont in Journ. de Botaniq. iv. 355 (1890); 

 in Ann. Sci. Nat. I. c. 175-8, t. 5, f. 6, 9 (1892). UsciHatona Retzii 

 Ag. Dispos. Algar. Suec. 36 (1812). Crass, trich. 9-5-10-5 /x. 



Pungo Andougo. Ad muscos (Jungermannias) submersas in 

 rivulo Tangue pr. Catete ; May 1857. No. 165. 



7. P. AUTUMNALE (Ag.) Gomont in Ann. Sci. Nat. I. c. 187-190, 

 t. 5, f. 23, 24 (1892). Oscillatoria antunmalis Ag. I.e. 36 (1812). 



Forma tenuis. Crass, trich. 38 /x. 



Golungo Alto. Cum P. laiuinoso ad terram limosam post pluvias ; 

 Dec. 1855. No. 166. 



4. Proterendothrix, gen. n. 

 Plauta; miuutK, primum endophyticae, tum opiphytica; ; fila 

 solitaria vel 2-3 associata, brevia et simplicia ; vagiuje achro^e, 

 hyalime et ampbe, marginibus irregularibus ; trichomata soliiaria 

 intra vaginam unamquauique. 



1. P. scolecoldea, sp. unica (tab. 365, figs. 3-6). P. tricho- 

 matibus a^rugineis et liexuobis, apicibus sajpe subattenuatis; cellulis 

 subquadratis vel diametro paullo brevioribus. Crass, fil. 9*5-19 /x; 

 crass, trich. 4-5-5'5 y-. 



Huilla. In Porphyrosiphone Notarisii, prope lac. Ivantala ; 

 March 1860. Nos. 17 and 18. 



