68 Annals of the South African Museum. 



Family NOSTOCACEJE. 



35. Anabcena cylindrica, Lemm., in Forschungsber. Biol. Stat. 

 Plon, iv., 1896, p. 186, f. 8-12. 



Crass, cell. 3-35^ ; lat. heterocyst. 58-6 /u, long, heterocyst. 8^u ; 

 long. spor. 14-19 jj., lat. spor. 5-5-6^. 



Upper (or Composite) Region. On mud in the river-bed, Holle 

 River; 10.12.08. 



Little Namaqualand. In spring at Henkriesfontein ; 14.1.09. 



36. Nodularia turicensis, (Cramer) Hansg. (= N. Harveyana, 

 Born. & Flah.) 



Little Namaqualand. Attached to stones in running water at 

 Henkriesfontein ; 14.1.09. 



37. Nostoc paludosum Kiitz. 



Little Namaqualand. Floating in dam at Rozynbosch ; 9.1.09. 



Family RIVULARIACEtE. 



38. Homceothrix africana, G. S. West, sp. n. 



H. fills parvis, sparsis inter protonema muscorum, subrectis vel 

 curvato-flexuosis, plerumque curtis ; vagina arcta et firma, in fills 

 juvenibus hyalinis et achrois, in filis vetustis lamellosis et aureo- 

 brunneis ; trichomatibus brevibus, ab base gradatim et gradatim in 

 pilum subobtusum brevem attenuatis, inter cellulas non constrictis ; 

 cellulis inferioribus diametro paullo brevioribus, plerumque paene 

 subquadratis, iis superioribus tarn longis quam latis vel diametro 

 liV-plo longioribus ; cellula basali hemisphaerica ; cellula apicali 

 obtusa ; heterocystis nullis. 



Crass, fil. ad bas. 7 - 8-ll - 5^; crass, trich. ad bas. 5 - 8-6 - 3 fx. 

 (Figs. 36, 37.) 



Great Namaqualand. Among moss-protonema on drying mud in 

 Lowen's River, Gawachab ; 7.2.09. 



This appears to be a distinctive species, but should be compared 

 with another African species, H. cartilaginea nov. comb. ( = Calothrix 

 cartilaginea, G. S. West, in Journ. Linn. Soc. Bot. xxxviii, 1907, 

 p. 181, t. 10, f. 7), which has been found in Tanganyika. It differs 

 from that species in the absence of the cartilaginous stratum, and in 

 the much more cylindrical trichomes, which are not torulose and 

 are without a basal swelling. The sheaths also differ in becoming 

 golden-brown and lamellose in the older filaments. 



