M3^ophyceae 267 



Plate XVII. fig. 12. 



Filaments 5-15 mic. in diameter, sometimes thickened in lower portion; 

 trichomes 3.5-5.5 mic. in diameter; heterocysts equal to or exceeding the 

 basal cells in diameter; gonidia 8 mic. in diameter, 8-10 mic. in length, 

 single, rarely in pairs, somewhat quadrate, angular-convex, rotund. 



Hawaii. On filaments ofPithophora affinis. Near Hilo, Hawaii. 

 July 1889. (Lauterbach). 



481. Calothrix breviarticulata West and West. Welwitsch's African Fresh- 

 water Algae. Journ. of Bot. 35: 240. 1897. De Toni. Syll. Algar. 

 5: 620. 1907. 



West. West Indian Freshwater Algae. Journ. of Bot. 42: 293. 1904. 



Filaments 15-16 mic. at the base, 11.5-12.5 mic. in middle portions, up to 

 380 mic. in length, solitary or gregarious, gradually tapering from base to 

 apex; sheaths thick, lamellose, becoming brownish black in old plants; trich- 

 omes 8.5 mic. in diameter at the base, 5.5-7.5 mic. in middle portions; cells 

 disc-shaped, four or five times shorter than their diameter; heterocysts soli- 

 tary, basal, hemispherical; cell contents pale blue-green. 



West Indies. Epiphytic on Vaucheria species. Royal Botanical 

 Gardens, St. Ann's, Trinidad. (Howard). 



• 482. Calothrix violacea (Wolle) De Toni. Syll. Algar. 5: 619. 1907. 



WoUe. Fresh Water Algae. II. Bull. Torn Bot. Club. 6: 138. 1877- 

 (M astigonema violacea Wolle). 



Filaments 15-18 mic. in diameter, parasitic, usually in clusters, ten or 

 twelve arising from each base, "a sort of warty excrescence," when young 

 blue-green, changing when mature to purplish iron or amethyst color, final- 

 ly becoming olivaceous brown; sheaths wide, often truncate, almost color- 

 less; trichomes 7-9 mic. in diameter; lower cells short, two or four times 

 shorter than the diameter, upper cells longer, finally four or six times as 

 long as wide; heterocysts more or less compressed. 



Pennsylvania. "Parasitic on Plectonema in shallow river waters." 

 < Wolle). 



483. Calothrix adscendens (Naegeli) Bornet and Flahault. Revis. des Nos- 

 toc. Ann. Sci. Nat. Bot. VII. 3: 365- 1886. De Toni. Syll. Algar. 

 5: 620. 1907. 

 Wolle. Algae Exsicc. no. 83. (M astigonema parasiticum 



Wolle). Setchell. Notes on Cyanophyceae. III. Erythea. 7: 46. 1899. 



Plate XVII. fig. 13, 14- 



Filaments 18-24 mic. in diameter, i mm. in length, scattered or gre- 

 garious, light blue-green in dried material, tapering from base to apex; 

 sheaths thick, gelatinous, lamellose, finally becoming ocreate, transparent; 

 trichomes 12 mic. in diameter in the middle portions; cells equal to the 

 <iiameter in length or shorter; heterocysts basal. 



Pennsylvania(?). (Wolle). 



