FRESH-WATER ALG.E OF THE UNITED STATES. 77 



Fig. 4 a, pi. 9, reproscnts a frond of this plant magnified 125 diameters; fig. 4 h, 

 a fragment magnified 460 diameters. 



Professor Bailey, in American Journal of Sciences, vol. iii., new series, states 

 that he has found two species of the genus Sthjonema, namely, St. afroviren-f, Ag. 

 and St. mammillosum , Ag. ; the former growing on wet rocks at Indian Falls, 

 Putnam County, New York ; the latter at liound Pond, near West Point. I have 

 no personal knowledge of the genus, but, according to authorities, it belongs to 

 the lichens rather than the algae, apothecia having been detected in various 

 species. 



Class CIII.OKOPIIYLLACE^.^ 



Plantidce aqnaticiE vel aerea?, luii-, bi-, vol multicelliilai'cs, aut singula3 

 aiit consociata^', faniilias forniantes. 



Vegctatio terminalis vel non terminalis. 



Ramificatio aut nulla aut vera, sed ccllularum non divisione, potius 

 proliticatione. 



Cytioderma non siliceum, combustibile, sa^pius e stratis successivis 

 compositura, substantiam gelatinosam plerunique liquidam exsudans. 



Ciltiophsma cliloropliyllosum, cblornphylli loco nonnunquam erythrino 

 vel substantia oleosa coccinea, carnea aut rufescente coloratum, luieleo 

 (eentrali vel lateral!) plerumque prjijditum, granulis amylaceis rarissime 

 carens. 



MuUiplicafio fit cellularum divisione vegetativa. Foecundatio j^le- 

 I'umque sexualis. 



Propagatlo fit aut oosporis vel zygosporis aut gonidiis tranquillis vel 

 agilibus. 



Aquatic or aerial wax-, bi-, or multicellidar i)lants occurring singly, or 

 consociated in fiimilies. 



Vegetation terminal or not so. 



Brandies either wanting, or if present, true branches, although formed 

 rather by a process of proliferation tlian division of the cells. 



Cytioderm not siliceous, combustible, often composed of successive 

 strata. 



Cytioplasm chlorophyllous, sometimes colored by an oily crimson, flesh- 

 colored or yellowish-red substance, in the place of the chlorophyl, gene- 

 rally fm-nished with a nucleus (either lateral or central), very rarely 

 without starch granules. Growth occm'ring by the division of the cells. 

 Fecundation generally sexual. 



Propagation taking place by oospores or zygospores, or by tranquil or 

 motile gonidias. 



' The description of this Class and Order is that of Prof. Italindiorst. 



