The Freshwater Algae of Africa. 539 



(g) OEDOGONIALES. 



(1) OEDOGOXIACEAE. 



Genus OEDOGONIUM Link. 



1. Oedogonium crassum (Hass.), Wittr. ; Hirn, Monogr. u. Iconogr. 

 d. Oedogoniaceen, 1900, p. 139, Tab. XVIII, fig. 99. 



Samples 53, 54, and 55 (common). 

 Crassit. cell, veget., 40-63 /i ; altit., 3-4 plo major, 

 oogon., 72-84 /<.; ,, 120-133//. 



oospov., 66-72 \>. ; „ 85-90 \>-. 



cell, antherid., 40 fi ; „ 9-10 //. 

 The dimensions are slightly larger than those given by Hirn. In 

 samples 54 and 55 a few male threads were observed, but in none of 

 them were the antheridia more than 0-celled, and the contents were 

 too disintegrated to show the number of sperms. 



2. Oedogonium crispum (Hass.), Wittr. ; Hirn, op. cit, p. 159, 

 Tab. XXV, fig. 138. 



Samples 53, 54, and 55 (not very common). 

 Crassit. cell, veget., 12-15 />. ; altit., 3-5 plo major. 



,, oogon., 36-50 \i ; „ 49-60 fi. 



,, oospor., 40 46 \i. 



3. Oedogonium pisanum, Wittr. ; Him., op. cit., p. 181, Tab. XXIX. 

 tig. 175. 



Sample '36. 



Crassit. cell, veget., 8-15 /u ; altit., 2-4 plo major. 

 „ oogon., 27-32 /x ; „ 40-45//. 



The basal attaching cell was very much elongated. The apex of the 

 filaments was usually gradually attenuated to a long hair, the cells 

 becoming progressively longer ami narrower until the terminal, very 

 much elongated hair-cell, with very scanty contents, was reached. 



4. ? Oedogonium boreale, Hirn, op. cit.. pp. 275. 27*i, Tab. XLVII. 

 fig. 300 : forma 



Samples 29, 30a. 



I have some little doubl whether the Oedogonium in these samples 

 is really Hirn's species, which, as far as I am aware, lias hitherto only 

 been recorded from Finland. My determination is lased on the 

 finding of a single oogonium with dwarf-males (crass, oogon, 55 fi ; 

 altit. oogon., 69 // : crass, nannandr., 20 // ; altit., 27 /<). The vege- 



