70 SPECIES OF ALG.E. 



b. " thin, skin-like, expanded gracilis, 306 



b. " dense gelatinous, on partly submerged stones, 



heterotrichum, 307 



104. OSCILLARIA. 



Articulations indistinct (a). 



'• about as long as wide (c). 



" one-half " " " " \d). 



" less than half as long as wide (/). 

 In hot water from waste steam pipes; diam. 1.8-2.8/^, 



amphibia, 310 



