BY G. I. PLAYFAIR. 



507 



Cylindrospermum Goetzei Schm., forma. (PL liv., f.26, 27). 



Trichoniata cUigusta, ad genicula constricta; cellulis quadratis 

 vel cyliiidraceis, disjunctis: heterocy«tidibus oblongis vel conicis; 

 goiiidiis laiiceolati.s vel subdoliformibus, apicibus arigustis truii- 

 catis. 



Cell, diaiii. .'^5, alt. 4-10; heterocyst. 3-6, alt. 6-14; gonid. 7-10, 



alt. 14-2: 



Lismore (306). 



C rectangulare Flayt, parthn, Frw. Alg. Lismore, p. 349, f. A. 

 Of. Schmidle, Schiz. Conj. Chlor. in Engler's Flora von Afrika, 

 H. xxii., p. 2 4 5, T. iv., f.5. In this, as in all other species of the 

 family, the cells and heterocysts may vary much in shape and 

 size, but the form of the gonidia is characteristic. With the 

 three species of Cylindrospermjim mentioned above, compare 

 Anah(Hna oscUlarioides (type), its var. stenosj^oi-a Born. <fe Flah., 

 and A. Volzii Lemm. These show the same three allotropic 

 forms of gonidia in what is, biologically, one species; they are all 

 found here with the same (quadrate or cylindrical) cells and 

 heterocysts, very often also accompanying one another. 

 Fam. SCYTONEMACE.^. 



Genus T o l y p o t h r i x Kiitz. 

 ToLYPOTHRix LANATA (Desv. ) Wartmanii. 

 (Text-fig. 3). 

 Diam. fil. 15-17, trich. 14; cell. alt. 4-8 

 (plerumque 4); heterocyst. 15 x 14//. 

 Grafton, Nymboidia R. (265). 

 Our specimens agree in dimensions 

 fairly well with those given by Raben- 

 horst, Fl. Eur. Alg., ii., p. 277 (fil. diam. 

 14-181-, trich. 11-15/x), but the cells are 

 much shorter (equal to, slightly less than, 

 or half as long as the diameter — Rabh.). 

 Hheatli colourless, J to IJ/x thick, trich- 

 omes constricted at the dissepiments, 

 cytoplasm pale green or pale grey-green, 

 very finely granular. 

 Text-fig. 3. — Tolypothrix lanata (Desv.) Wartmann; ( x 660. 



