WELWITSGH S AFRICAN FRESHWATER ALG^E. 39 



oblique spbericis, cum processu mamillato solido projectente intra 

 extremitates curvatas cellulte ad polum unumquemque, a latere 

 visis globosis cum processibus exacte oppositis ad polos ; sporis 

 membranis tribus, membrana mediana luteo-fusca et scrobiculata, 

 membrana exterior! acbroa et ad polum unumquemque uuus pro- 

 cessuura fit. Grass, cell, veget. 6-7 //■ ; long, aplanosp. sine proc. 

 27-29 /x, cum proc. 42-46 /x ; lat. aplanosp. 27-28 /x. 



Huilla. Alga late viridis, lubrica ad rapes submersas de Morro 

 de Lopollo ; Febr. 1860. No. 186. Inter Temnoganietwn hetero- 

 sponim, Morro de Lopollo ; Febr. 1860. No. 172. In paludibus 

 exsiccandis ; April 1860. No. 176. Inter Microspuram Ldfiji-enii, 

 Morro de Lopollo ; May 1860. No. 182. 



Tbis is a most cbaracteristic species ; spores witb processes of 

 tbis nature are possessed only by two otber algas in tbe order 

 Zyr/nemacctB, viz, Mour/eotia uherosperina and M. irregularis. Tbe 

 consecutive spores, wbicli are very large, are alternately oblique, 

 the cells containing tbem being very slightly bent alternately to the 

 right and left. 



3. Pyxispora, gen. n. 



Cellulte vegetativfe ut in Zipinema, conjugatione scalariformi ; 

 zygosporae tubam conjugantem totam inter filamenta complentes ; 

 zygospore e parte solum contenti cellularum formatae, elliptico- 

 oblongte vel ellipsoidfe cum porca cingente in plauitie diametrorum 

 brevissimorum et rima circumscissa secundum porcam, 



1. P. mirabilis, sp. unica. P. cellulis vegetativis diametro 

 14^-4^-plo longioribus, chromatophoris subdistinctis, pyrenoide 

 parvo subgloboso ellipticove in chromatophoro unoquoque ; tuba 

 conjugante supra porcam zygospore iudistincte visa. Crass, cell, 

 veget. 12-13-5 p.; long, zygosp. 19-23 p, lat. 13-5-17 /x. 



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



The fact that only a portion of the contents of the conjugating 

 cells participates in the formation of the zygospore indicates a 

 relationship to the fam. Mesocarpece, although the arrangement of 

 the chromatophores in the ordinary vegetative cells much resembles 

 the arrangement in the genus Zyynema (fam. Zi/(jnemece). The 

 character of the zygospores is, however, quite unique, and the 

 plant must therefore be placed in a new family, Pyxisporece. 



4. Zygnema Ag. (1824). 



1. Z.ERicETORUM (Kiitz.) Hansg. in.:I;-c/i/y. Naturw. Landesdurchf. 

 von Buhmen, Bd. vi. 155-6 (1888). Zygogonium ericetorum Kiitz. 

 Phyc. Gener. 280 (1843). Crass, cell, veget. 27-32 /x ; diametro 

 lJ-3 plo longioribus. 



Pungo Andongo. Inter (Edogonium sp. ad limum juxta rivulum 

 de Casalale ; Febr. 1857. No. 106. Inter (Edogonium Hothii f. 

 major ad ramulos Podostemacearum in rivulis (Casalale) ; March 

 1857. No. 105. Ad Podostemaceas in riv. de Cabondo ; Febr. 

 1857. No. 108. 



Huilla. In udis sylvaticis et apricis inter Monino et lac. Ivan- 

 tala ; April 1860. No. 14. In paludibus exsiccandis ; April 1860. 

 No. 176 ; crass, cell, veget. 27-34 p ; diametro 1-3-plo longioribus. 



