82 



THE JOURNAL OP BOTANY 



p. 181. Coelastrum Stuhlmanni Schmidle, 1900. Diam. cell. 

 25-30 /.. 



Hah. Albert Nyanza. 



I agree with Ostenfeld that it is scarcely possible to separate 

 this forrQ as a distinct species. It differs from C. camhricum 

 Arch, (a species which for some unknown reason most French 

 and German authors seem very reluctant to recognize) only in the 

 ridges which radiate from the external projection of each cell. 

 The fact that Ostenfeld has found intermediate stages with the 

 ridges developed in various degrees is almost conclusive evidence 

 that C. Stuhlmanni is but an extreme form of C. camhricum. It 

 is probably a warm -water form. 



10. Spirogyra angustissima, sp. n. S. cellulis vegetativis 

 angustissimis, diametro 18-23-plo longioribus, extremitatibus non 

 replicatis ; chromatophora singula, angusta, in parte 

 mediana cellulee locata, marginibus irregulariter un- 

 dulatis et pyrenoidibus minutis, anfractibus laxis 

 4^-5. Crass, cell. 4-2-4-5 /x. Cellulse fructiferge et 

 zygosporae ignotse. (Fig. 2.) 



Hah. In swamp, Kota Kota, Lake Nyasa. 

 It is, as a rule, very undesirable that species of 

 any genus of the Zygnemacece, should be established 

 solely on vegetative characters, but the vegetative 

 filaments of this slender African species differ so 

 much from those of previously described species that 

 it seems advisable to give it a distinctive name. It 

 is much the narrowest species of the genus, being 

 less than half the diameter of the smallest Sjni'ogijra 

 previously known. The solitary chromatophore is 

 small and narrow, and occupies only the median 

 third of the cell. It has from 4| to 5 rather lax 

 spiral twists, and scattered through it at intervals 

 are minute pyrenoids. 



One would imagine that the fructiferous cells 

 (female) must be considerably inflated in order to 

 accommodate a zygospore, but these yet remain to 

 be discovered. 



The Alga occurred in no. 18 of Dr. Cunnington's 

 numerous collections of the Third Tanganyika Ex- 

 pedition of 1904-5, all of which are in the British 

 Museum. It w^as found rather sparingly amongst 

 conjugating examples of Deharya africana G. S. West. 



I 11. Closterium moniliferum (Bory) Ehrenb. 



\ — I Rather large specimens: — Long. 204 /x; lat. 55 /x; 

 lat. apic. circ. 5 /x. 



Hah. Albert Nyanza. 



12. MiCRASTERiAS Itzigsohnii Braun in Br6b. 



" Liste Desm. Basse-Normandie," Mem. d. 1. soc. 

 imp. des Sci. Nat. Cherbourg, iv. 1856, p. 121, t. 1, 

 Long. 56 IX ; lat. 61 /x ; lat. isthm. 14 /x. (Fig. 3, A.) 



Fig. 2.— Spi- 

 rogyra angus- 

 tissima, sp. n. 

 Vegetative cell, 

 X 1000. 



f. 2. 



