338 X. zYGNEMACEiE (West). [Mottgeotia 



5. Moug-eotise sp., I.e. 



HuiLLA. — Inter Utriculariam cymbantham, Morro de LopoUo ; April 

 1860. No. 179. 



Conjugation incomplete ; conjugating cells much bent. 



2. GONATONEMA Wittr. (1878). 



1. G. tropicum W. et G. S. West in Journ. Bot. 1897, p. 38. 



HuiLLA. — Alga laete viridis, lubrica ad rupes submersas de Morro de 

 LopoUo ; Feb. 1860. No. 186. Inter Temnogametum heterosjjorum, 

 Morro de LopoUo ; Feb. 1860. No. 172. In paludibus exsiccandia ; 

 April 1860. No. 176. Inter Microsjxiram Lcifgrenii, Morro de LopoUo ; 

 May 1860. No. 182. 



This is a most characteristic species ; spores with processes of 

 this nature are possessed only by two other algse in the order 

 .Zf/gnenuicedi, viz. Mougeolia uherospenna and M. irregularis. The 

 consecutive spores, which are very large, are alternately oblique, the 

 cells containing them being very slightly bent alternately to the 

 right and left. 



3. PYXISPORA W. et G. S. West in Journ. Bot. 1897, p. 39. 

 1. P. mirabilis W. et G. S. West, l.c 



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. Mesocarjjece, although the arrangement of the chromato- 

 phores in the ordinary vegetative cells much resembles the arrangement 

 in the genus Zygnema (fam. Zijgnemav). The character of the 

 zygospores is, however, quite unique, and the plant has therefore 

 been placed in a new family, Pyxisporece . 



4. ZYGNEMA Ag. (1824). 



1. Z. ericetorum Hansg. in Archiv. Naturw, Landesdurchf. von 

 Bohmen, Bd. vi. 155-6 (1888) ; W. et G. S. West in Journ. Bot. 

 1897, p. 39. 



Zygogoniimi ericetorum Kiitz. Phyc. Gener. 280 (1843). 



PuNOO Andongo. — Inter CEdngonii sp. ad limum juxta rivulum 

 de Casalale ipsius Prsesidii ; Feb. 1857. No. 106. Inter (Edogonii 

 Rothii f. majorem ad ramulos Podostemacearum in rivulis Prassidii 

 (Casalale) ; March 1857. No. 105 Ad Podostemaceas (Tristicha 

 trifnria Tul.) in riv. de Cabondo ; Feb. 1857. No. 108. 



HuiLLA. — In udis sylvaticis et apricis inter Monino et lac. Ivantala ; 

 April 1860. No. 14. In paludibus exsicoandis ; April 1860. No. 176. 



2. Z. spontaneum Nordst. Alg. et Char. Sand vie. 17, t. i. f. 

 23-24 (1878); W. et G. S. West in Journ. Bot. 1897, p. 40. 



HuiLLA. — Inter Gonatonema tropicum, Temnogametum heteroxporum, 

 etc., Morro de LopoUo ; Feb. 1860. No. 172. 



This most interesting species has very remarkable spores both with 

 regard to their 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. 

 The relationship between the aplanospores and zygospores in this 

 species is in all respects comparable to that between those of Z. 

 ■pachydermum, West ; in the latter species the aplanospores are also 

 smaller, globose, and possess a thinner membrane. 



