Temnogametum] ix. temnogametaoEjB (West). 337 



filaments put out short rounded conjugating tubes which unite, the 

 cells themselves becoming bent towards each other, and very soon 

 the two cells coalesce and form the zygospore. In this way a zygospore 

 is produced which at first sight very much resembles the central cell 

 of the five cells constituting the spore of a Mougeotia of the section 

 Staurospermeee,. In those filaments in which the pairs of cells are cut 

 ofE the conjugation is lateral, the two cells forming a zygospore much 

 resembling the aplanospore of a Gonatonema. In fact, these zygo- 

 spores are oblique, and the convexities and concavities alternate along 

 the filament precisely as in the case of a sporif erous filament of the 

 latter genus. 



Both scalariform and lateral conjugation occur in the same filaments. 

 In all the specimens observed (which had been dry for a loug period) 

 the contents of the thick-walled spores appeared to have contracted 

 into two approximate rounded masses ; whether the latter had ever 

 been perfectly united or had yet to unite within the wall of the 

 spore is a matter that could not be definitely decided from the 

 material. 



On account of the peculiar conjugation, this plant has been placed as 

 the type of a new order — Temnogametacem — of Conjugatce. 



X. ZYGNEMACE^. 

 1. MOUGEOTIA Ag. (1824); em. Wittr. (1878). 



1. M. (§ Staurospermum) uberosperma W. et G. S. West in 

 Journ. Bot. 1897, p. 37. 



HuiLLA. — In paludibus exsiccandis ; April 1860. No. 176. 



This characteristic species belongs to the section Staurospermum ; in 

 maturely conjugated specimens this can only be inferred from the 

 genuflexed conjugating cells, but the young zygospores are subrectan- 

 gular or subquadrate. The four processes present on the zygospores 

 are developed very early, considerably before the zygospores are ripe, 

 and are rarely of equal length ; they are of the same diameter as the 

 vegetative cells, and fit into them very closely. 



2. M. (§ Staurospermum) irregularis W. et G. S. West in Journ. 

 Bot. 1897, p. 38'. 



PuNGO Andongo. — In pascuis spongiosis breviter gramiuosis juxta 

 rupes gigant. Prsesidii prope Catete ; May 1857. No. 111. 



The nearest species to this is M. capucina (Bory) Ag., from which 

 it is distinguished by its size, its colour, and its curious zygospores. 



3. M. (§ Craterospermum) angolensis W. et G. 8. West in 

 Journ. Bot. 1897, p. 38. 



PuNGO Andongo. — Ad ramulos Podostemacearum (Trisiicha trifaria 

 TuL) in rivulis Prsesidii (CasalaW), inter CEdogonii Rothii f. majorem ; 

 March 1857. No. 105. 



This species differs from M. Imtevirens (A. Br.) Wittr. chiefly in the 

 chromatophores each possessing a much fewer number of pyrenoids, 

 and in the much smaller zygospores. 



i. Mougeotiae sp. W. et G. S. West, I.e. 



HuiLLA. — Ad culmos Eleocharidis fluitantis in rivulis de Morro de 

 Lopollo (5300 ped. altit.) ; Feb. 1860. No. 188. 



MossAMBDES. — Freq. in stagnis puris ad ripas flum. Bero ; Aug. 

 1859. No. 190. 



