VAUCHERIA. 149 



YAUCHERIA DICHOTOMA, Lyngb. 



Large, robust, loosely caespitose, dirty green or becom- 

 ing brownish. Filaments thick, setaceous, nearly a foot 

 long, remotely clichotoiiious. Oogonia sessile, globose or 

 ovoid, single, scattered, or two or more approximating. 

 Oospores, when mature, with a triple membrane, spotted 

 with brown. Antheridia single, erect oval, subclavate or 

 acute, on the same or 011 different filaments. 



Diameter of filaments variable, 100-200 /*. 

 Diameter of oogonia, about 100 /*. 



In ditches, marshy places around limestone springs. Good 

 fertile specimens rare. 



In similar localities there are other species growing in 

 large dense mats, but short filaments ; V. dichotoma is dis- 

 tinguished by its much longer filaments, usually 3-6 inches 

 long, and more bushy growth. 



Syn. Conferva dichotomy Linn. 5 Vaucheria globifera, D.By. ; 

 Vaucheria salina, Kg. ; Conferva dichotoma setis porcinis, 

 Dill. 



Plate CXXVI, figs. 1-3, parts of dichotomose branching 

 filaments ; figs. 4-6, sessile oogonia ; fig. 7, one of the 

 swollen ends ejecting microgouidia. 



VAUCHERIA THURETII, Woron. 



Forms cheerful, deep olive green, velvet-like mats often 

 feet in extent. Filaments upright, close, from a closely in- 

 terwoven substratum, in salt marshes along the eastern shores 

 of New Jersey ; dried it becomes dark brown or blackish. 

 Size of filaments, 50 yw more or less ; oogonia large, globose 

 or ovoid, sessile or subsessile 125-150 yw diameter. Anthe- 

 ridia rare, 011 same filament with oogonia. 



Plate CXXVI, figs. 11-15, sections of filaments from New 

 Jersey specimens. 



VAUCHERIA AVERSA, Hass. 



Loosely caespitose, sparingly branched, expanding in all 

 directions, filaments thick ; oogonia erect or suberect, sessile 

 or subpedicellate ; antheridia, cylindrical or subclavate, 

 erect, ends more or less curved. (European forms not erect 5 

 sub-horizontal.) 



Diameter of filaments, 100 }JL more or less. 



