SIROSIPHON. 273 



Diameter of filaments, about 50 yw ; branches 38 yw, more 

 or less, with sheath ; without sheath, 20-25 /x 



On slopes of Mount Tahawas, in the Adirondack Moun- 

 tains, N. Y., at an altitude of about 5000 feet, over which 

 water is continually dripping, this plant nourishes, forming 

 a turfy coating, yards in extent. The specimens agree 

 well with the description of the European, Alpine plant, 

 found at practically the same altitude. (Wood's Contribution 

 Fresh- Water Algce, p. 71.) 



Plate CXCIV, figs. 11-16, taken from specimens found in 

 New Jersey, answering the description, but given not with- 

 out a suspicion that they are closely related to 8. ocellatus. 



SIROSIPHON LIGNICOLA, Wood. 



Occuring in small black spots, often aggregated, forming 

 extended tomentose strata. Filaments much branched, 

 green, golden, or brown ; branches straight or variously 

 curved ; sometimes very much contorted and interwoven ; 

 their apices obtusely rounded or subacuminate ; cells 1-2 or 

 more seriate, light or deep aeruginous, irregular ; terminal 

 parts of trichornes sometimes cylindrical; shortly arti- 

 culate, granulate; sheaths somewhat ample, not trans- 

 parent, fuscous or ferruginous. 



Diameter of filaments variable, from 12-30 yw. Most com- 

 monly, 15-20 }JL. 



Frequent on old wood and on the trunks of trees in South 

 Carolina. During the past eight or ten years I have received 

 scores of specimens collected by the indefatigable W. H. 

 Ravenel, of Aiken, South Carolina. The collections \vere 

 made in various seasons of the year, and from the trunks of 

 many kinds of trees, in dry, and in continuous wet weather. 

 Sirosiphon is at best a very polymorphic algse. A few speci- 

 mens illustrate this fact, but when many of the same genus 

 are brought together from the same habitat, it becomes 

 utterly impossible to separate them into different species. 

 We therefore unite the species 8. guttula, Wood ; and S. 

 acervatum, Wood, with S. lignieola, Wood. 



Plate CXCIII, figs. 1, 2, two well developed forms ; figs. 

 3, 4, an occasional appearance of a distorted growth ; figs. 

 5-11, conditions of young developing plants. 



SIROSIPHON ARGILLACEUS, Wood. 



Stratum thin, expanded, blackish, sub-niembranaceous ; 

 filaments short, densely intricate and frequently somewhat 

 concreted, giving origin to numerous irregular branches ; 



