146 Minnesota Algae 



Plant mass 1-2 mm. in height; rust-colored, dense; fascicles 4-10 mm. 

 in height; sheaths 15-40 mic. in thickness, often surrounding two, three 

 or many trichomes; trichomes 2.5-3.5 ™ic. in diameter. 



West Indies. On rocks. Roseau Valley (1000-2000 ft.), Dominica; on 

 bark, windward road to lake, Dominica; on the ground, mostly in old 

 Diablotia holes, Morne Anglais (2300 ft.). (Elliott). 



282. Ssrmplocastrum friesii (Agardh) Kirchner in Engler and Prantl. Die 



natiirlichen Pflanzenfamilien. I. i. a. 68. f. 53. 1900. Gomont. Mon- 



ogr. Oscill. 54. pi. 9. f. I, 2. 1893. (Schizothrix friesii 



Gom). De Toni. Syll. Algar. 5: 347. 1907. 



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



(Symploca lucifuga Breb.); Fresh Water Algae. III. Bull. Torr. 



Bot. Club. 6: 183. 1877. (Symploca friesiana Kg.); Fresh- Water 



Algae U. S. 303. pi. 205. f. 8; 304. pi. 205. f. 13. 1887. Moebius. Ueber 



einege in Portorico gesammelte Siisswasser- und Luft-Algen. Hedwigia. 



2T. 246. 1888. WoUe and Martindale., Algae. Britton's Catalogue of 



Plants found in New Jersey. Geol. Surv. N. J. 2: 608. 1889. Collins, 



Holden and Setchell. Phyc. Bor.-Am. Fasc. 11. no. 503. 1898.' Collins. 



Notes on Algae. I. Rhodora. i: 10. 1899. 



Plate VI. fig. 10. 



Plant mass indefinite, expanded, black or olive or lead-colored; fila- 

 ments in lower portions twisted and entangled, in upper parts somewhat 

 straight, parallel, dichotomously divided and branched into appressed por- 

 tions, forming rigid, erect, spine-shaped tufts 3 cm. or more in height; 

 sheaths cylindrical, firm, pointed at the apex, lamellose, smooth or a 

 little roughened in outline; trichomes 3-6 mic. in diameter, evidently 

 constricted at the joints, few or solitary within the sheath, parallel; apical 

 cell truncate conical; cells 4-1 1 mic. in length; cell contents coarsely gran- 

 ular (except in apical cell). 



Canada. On old wood. (Macoun). United States. (Farlow). 



Maine. On ground in woods at the base of Mount Kineo. July 1897. (Col- 

 lins). Massachusetts. On damp ground. August 1898; abundant in paths 

 and by roadsides. Lynnwoods, Middlesex Fells. 1899. (Collins). New 

 Jersey. On shaded clay banks. Bergen. (WoUe). West Indies. Growing 

 upon moss. On Mt. Jimenez, Sierro de Luquillo, Porto Rico. (Sintenis). 



Genus INACTIS Kuetzing. Tab. Phyc. i: 44. 1845-1849. 



Plants growing in moist places or in rivers; filaments caespitose, often 

 with numerous false branches, forming cushions which finally often 

 become encrusted with calcium carbonate and hardened, zonate within, 

 or aggregated into penicillate, floating fascicles; sheaths colorless or near- 

 ly so. 



I Plant mass cushion-shaped, tufted 



I Plant mass strongly encrusted with calcium carbonate, stony; fila- 

 ments straight, somewhat simple; trichomes 1-2 mic. in diameter; 

 cells somewhat quadrate I. pulvinata 



