40 WELWITSCH's AFRICAN FRESHWATER ALG.E. 



2. Z. SPONTANEUM Noi'dst. Ah/, et Ch(i)\ Sandi'ic. 17, t. i. f. 23-24 

 (1878). Z, celluiis vegetativis diametro li-4-plo longioribus ; 

 conjugatione scalariforrai, celluiis fructiferis uon (vel levissime) 

 inflatis : zygosporis plerumque oblongis vel rotundo-ellipticis (raro 

 globosis), membraua crassa el aureo-brunnea, lamina mediana cum 

 scrobiculis magnis ; aplanosporis (cfr. cl. Nordst. 1. c.) zygosporis 

 similibus sed minoribiis, globosis, et membrana tenuiori. Crass, 

 cell, veget. 16-18 f/. ; crass, cell, fructif. 19-25 jt* ; long, zygosp. 

 24-31 /x, lat. 21-24 ^a. 



Huilla. Inter Goiiatimema trojncmii, TemnogameUnn heterosponnn, 

 &c., Morro de Lopollo ; Febr. 1800. No. 172. 



This most interesting species has very remarkable spores both 

 with regard to tiieir colour and markings. The original specimens 

 from the Sandwich Islands described by Dr. Nordstedt had only 

 aplanospores (hence the specific name) ; the African specimens 

 have only zygospores, and on account of their presence it has been 

 required to amend the description. The relationship between the 

 aplanospores and zygospores in this species is in all respects com- 

 parable to that between those of Z. pdchijdcrmnm West; in the 

 latter species the aplanospores are also smaller, globose, and possess 

 a thinner membrane. 



3. Zygnema sp. Crass, cell, veget. 15-21 /x ; diametro 3-6-plo 

 longioribus. 



Pungo Andongo. Cum Scytouemate in Pedra Songue ; April 

 1857. No. 153. 



5. Spirogyra Link (1820). 



1. Spirogyra sp. Cellulae vegetativae diametro (23 fx) circiter 

 3-plo longioribus, extremitatibus uon replicatis, chromatophoro uno, 

 anfractibus 1^ ; zyyosporis ellipticis, polls subacutis, membrana 

 glabra, luteo-fusca ; celluiis fructiferis subinflatis ; long, zygosp. 

 38-52 jji., lat. 23-30 [a. Prope .S'. arcttt (Ag.)Kiitz. var. catanijoriuis 

 (Hass.) Kirchn. 



Huilla. Inter alias algas in uligiuosis editioribus prope Hum- 

 pata, Empalanca et Lopollo ; May 1860. No. 15. Not in sufficient 

 quantity for absolute specific determination. 



2. Spirogyra sp. Cellulie vegetative^ diametro (36-5-46 fjt.) 2-3- 

 plo longioribus, extremitatibus non replicatis, chromatophoris 2, 

 anfractibus 3-4. 



Pungo Andongo. Inter Batrachospennuni nigrescens in flum. 

 Cuanza ; March 1857. No. 104. Ad rupes humidas juxta flum. 

 Cuanza; March 1857. No. 156. 



Golungo Alto. Cellulse vegetativse diametro (43-48 /*) 2-3|-plo 

 longioribus, extremitatibus non replicatis, chromatophoris 2, an- 

 fractibus circiter 4. Freq. in semistagnantibus ad ripas Rivi 

 Quiapoze, Camiuho pr. Mussengue ; Sept. 1855. No. 207. 



3. Spirogyra sp. Crass, cell, veget. 44-53 fx. 



Pungo Andongo. Ad ramulos Podostemacearum in rivulis ; 

 Marcb, 1857. No. 109. Nothing can be made out of the speci- 

 mens with any precision. Chromatophores 3 (?), edges smooth (?), 

 spirals lax. 



