Myxophyceae 221 



pulvinatum Nordst.). WoUe. Fresh Water Algae. Bull. Torr. Bot. 

 Club. 6: 283. 1879. (M astigonema velutinum Wolle) ; Fresh-Water 

 Algae U. S. 257. pi. 186. f. 1-6. 1887. (S. cortex ravenelii Wolle). 

 Collins. Algae of Middlesex County. 13. 1888. Lemmermann. Algenfl. 

 Sandwich.-Inseln. Bot. Jahrb. 34: 624. 1905. 



Plant mass dense, cushion-shaped, 1-2 mm. in thickness, widely ex- 

 panded, blackish green; filaments 15-21 mic. in diameter, coalesced in 

 vertical fascicles; false branches long, fiexuous, aggregated; sheaths firm, 

 membranaceous, lamellose, yellowish brown; trichomes 10-16 mic. in 

 diameter; cells somewhat quadrate or elongate; cell contents olive green. 



Massachusetts. In a greenhouse. Newton. (Farlow). New Jersey. 



Forming an extended olive green stratum, a little above the water level, 

 on the plank sides of a neglected basin of sea water. Perth Amboy. July 

 1878. (Wolle). Pennsylvania. On calcareous rocks. (Wolle). South 

 Carolina. Forming little turfy spots of a greenish color on bark. Growing 

 on twigs of a C e 1 1 i s and on bark of a willow. (Ravenel). Florida. On 

 trunks of various trees. (Smith). Hawaii. On volcanic gravel, Oahu. 



(Berggren, Schauinsland). 



406. Scytonema amplum West and West. On some Freshwater Algae from 



the West Indies. Journ. Linn. Soc. Bot. 30: 270. pi. 16. f. 14-16. 1895; 

 A Further Contribution to the Freshwater Algae of the West In- 

 dies. 1. c. 34: 287. 1900. De Toni. Syll. Algar. 5: 512. 1907. 



Plate XII. fig. 10, II. 



Plant mass small, woolly, 3-5 mm. in diameter, brownish; filaments 

 19-24 mic. in diameter, densely entangled;" false branches 13.5-16 mic. in 

 diameter, rare, usually in pairs but sometimes single, more slender than 

 the main filament; sheaths very wide, formed of parallel layers, in outer 

 portions gelatinous, colorless or somewhat yellowish, in the interior 

 abruptly yellowish or brownish; trichomes 3.5-4 mic. in diameter, narrow; 

 cells up to six times longer than the diameter; heterocysts oblong, several 

 times longer than their diameter; cell contents yellowish green. 



West Indies. On trees. Summit of Trois Pitons (4,500 feet). Novem- 

 ber, December. 1892; on rocks, Castle Bruce River (2,000-3,000 feet), Do- 

 minica. January, February 1896. (Elliott). 



407. Scytonema woUeanum De Toni. Syll. Algar. 5: 513. 1907. Wolle. 



Fresh Water Algae. Bull. Torr. Bot. Club. 6: 284. 1879; Fresh- 

 Water Algae U. S. 255. pi. 187. f. 1-3. 1887. (S. m i r a b i 1 e Wolle). 

 Plate XII. fig; 12. 

 Plant mass more or less widely expanded, olive becoming brownish; 

 filaments 20-25 mic. in diameter, strongly curved and fiexuous; false 

 branches 12.5-15 mic. in diameter, numerous, usually in pairs, adhering 

 usually without separation of the trichome at the end; sheaths firm, 

 smooth, olive or yellowish, rarely nearly colorless; trichomes often some- 

 what moniliform; cells two to three times shorter than their diameter. 

 Florida. On bark of Cypress trees. (Ravenel). 



408. Scytonema stuposum (Kuetzing) Bornet in Bornet and Thuret. Notes 



