Myxophyceae 151 



2 Plant mass caespitose or appressed, semiorbicular; sheaths very 



thick, lamellose; trichomes 4-9 mic. in diameter, usually solitary 

 within the sheath S. thelephoroides 



3 Plant mass indefinite, sheaths purple, orange or rose-colored; trich- 



omes 6-8 mic. in diameter, many within the sheath 



S. purpurascens 



4 Plant mass indefinite, woolly, lead-colored; sheaths very thick, 



lamellose; trichomes 7.5-8.5 mic. in diameter S. chalybea 



5 Plant mass not caespitose; sheaths yellowish orange; trichomes 7-13 



mic. in diameter; cells somewhat quadrate or twice as short as 

 the diameter S. muelleri 



II Cells longer than the diameter 



1 Filaments very long; sheaths dark lead-colored, irregular in out- 



line; trichomes 1.7 mic. in diameter S. braunii 



2 Filaments forming a loose, cobwebby mass within sandstone rock; 



sheaths cylindrical, rough, usually colorless and not lamellose, 

 sometimes brownish and lamellose; trichomes 3.5-4.8 mic. in 

 diameter; cells quadrate or a little longer than the diameter 



S. rupicola 



291. Schizothrix hyalina Kuetzing. Spec. Algar. 320. 1849. De Toni. Syll. 



Algar. 5: 360. 1907. 



Wolle. Fresh-Water Algae U. S. 307. pi. 203. f. 3, 4. 1887. (M i c r o c o- 

 leus hyalinus (Kg.) Kirchn.). Bennett. Plants of Rhode Island. 

 115. 1888. Wolle and Martindale. Algae. Britton's Catalogue of Plants 

 found in New Jersey. Geol. Surv. N. J. 2: 609. 1889. 



Plant mass thin, encrusted, often widely expanded or in tangled tufts 

 among other algae, blue-green or green; filaments 8 mic. in diameter; 

 sheaths colorless, very transparent; trichomes 1-1.5 mic. in diameter, con- 

 stricted at joints, very slender, curved and entangled, few within the 

 sheath; apex of trichome awl-shaped, pointed; cells somewhat quadrate; 

 c«ll contents pale green. 



Rhode Island. Davisville. (Bennett). New Jersey. In ponds on 

 Sphagnum. (Wolle). Pennsylvania. Wet rocks. (Wolle). South 

 Carolina. Wet ground. (Wolle). 



292. Schizothrix thelephoroides (Montagne) Gomont. Monogr. Oscill. 57. 



pi. 10. f. 1-4. 1893. De Toni. Syll. Algar. 5: 359- I907- 

 Moebius. Ueber einige in Portorico gesammelte Siisswasser- und Luft- 

 Algen. Hedwigia. 27: 247. pi. 9. f. 7- 1888. 



Plate VI. fig. 19. 

 Plant mass pannose, caespitose or appressed, semiorbicular, rust- 

 colored; filaments .5 cm. in height, divided and branched into appressed, 

 somewhat dichotomous divisions, forming more or less spirally twisted 

 tufts; sheaths firm, very thick, lamellose, the inner layers rust-colored, 

 the outer ones colorless, very frequently dilated below the pointed apex, 

 slightly roughened on the surface, transversely wrinkled; trichomes 4-9 

 mic. in diameter, usually solitary sometimes two within the sheath, parallel. 



