WELWITSCH's AFRICAN FRESH\\^ATER ALG.E. 241 



pilura crassum attenuatis, articulis ad basin depressis vel sub- 

 globosis, superioribus diametro duplo longioribus ; sporis cylindricis, 

 polis rotundatis, diametro 4-plo longioribus, episporium strato 

 singulo formatnni, flavo-brunneum et glabrum. Crass, trich. ad 

 bas. 7-9-5 /x; diam. beterocyst. 9-5 /x ; long. spor. 4G-50 /x ; lat. 

 spor. 12-5-13-5 fx. 



Mossamedes. Satis freq. inter Charae speciera in rivo Caroca 

 prope Cabo negro ; Sept. 1859. Nos. 19 and 173. 



Tbis species differs from G. nutans (Hedwig) Eabenb. Deutschl. 

 Kryptof/.- Flora, 90 (1847), in the length of its cells and in its spore?. 



XVI. — SlROSIPHONIACE^. 



1. Hapalosiphon Nag. (1849). 

 In tbis genus the spores are produced from the ordinary vege- 

 tative cells of certain of the plants. They are formed from the 

 majority of (or even all) the cells of both the primary filaments and 

 branches of some portions of these plants, and have always thick 

 yellowish-brown cell-walls. The outward form of the spores varies 

 with the different species, the dimensions being about those of the 

 vegetative cells. (Cfr. also Hansgirg in Oesterreich. Bat. Zeitschr. 

 xxxiv. 393 (1884) ; West in Jowii. Linn. Soc. xxx. 272, pi. xv. 

 f. 23-28.) In most of the species the branches arise at right angles 

 to the main filament, and the cell of the main filament directly 

 under the branch projects slightly into the sheath of the latter. 



1 . H. luteolus, sp. n. H. inter alias algas aquaticas in ciespitibus 

 minutis luteo-brunneis et dense intricatis repertus ; fills primariis 

 flexuosis, e serie singula cellularum formatis, vaginis firmis, amplis 

 et lutescentibus, cellulis reruginosis, oblongo-rectangularibus, sa^pe 

 subquadratis et diametro usque 3-plo longioribus, protoplasmate 

 granulato ; ramis solitariis, subremotis, elongatis et flexuosis (rarius 

 brevibus et subrectis), filo primario diametro asqualibus, apicibus 

 non attenuatis ; vaginis cellulisque iis filorum primariorum simili- 

 bus ; heterocystis intercalaribus, oblongo-rectangularibus (diametro 

 1^-3-plo longioribus) ; sporis subquadratis vel diametro paullo 

 longioribus. Crass, fil. 9'5-ll'5 /x; crass, cell. 5-5-6 [x. 



Iluilla. Inter alias algas, in uliginosis editioribus prope Hum- 

 pata, Empalanca et Lopollo, plagas spongiosas unacum Erio- 

 cauloneis, Xyridibus et Utriculariis constituens; May 18G0. No. 15. 

 In graminosis paludosis juxta rivulum Lopollo ; April 1860. No. 180. 

 Etiam Morro de Lopollo ; May 1860. No. 182. 



This species occurs in minute tufts, and the great resemblance 

 to each other of the primary filaments and branches, together with 

 their thick yellowish sheaths, characterize it. 



2. H. aureus, sp.n. H. inter alias algas aquaticas in ca^spitibus 

 aureo-brunneis dense intricatis repertus ; filis primariis tortuoso- 

 intricatis, e serie singula cellularum formatis, vaginis firmis, 

 tenaeibus, crassis, aureo-brunneis, hyalinis et in plantis vetnstis 

 puuctulatis, cellulis multe variabilibus, subquadratis vel subglo- 

 bosis, diametro brevioribus et subellipsoideis, oblongis et diametro 

 usque 7-8-plo longioribus ; ramis unilateralibns freqnentibus, 



Journal of Botany. — Vol. 35. [June, 1897.] R 



