164 MIDDLESEX FLORA. 



M. terrestris, Desmaz. 



Newton (W. G. Faiiow) ; Melrose. 

 M. versicolor, Thuret. 



Newton (W. G. Farlow). 



OsciLLARiA, Kuetz. 



O. subtorulosa, Farlow. 



Mystic river salt marshes. 

 O. chlorina, Kuetz. 



Newton (W. G. Farlow). 

 O. tenuis, Ag. • 



Maiden and Reading. 

 O. nigra, Vauch. 



Newton (W. G. Farlow) ; Maiden. 

 O. viridis, Vauch. 



Newton (W. G. Farlow). 

 O. subuliformis, Harv. 



Charles river salt marshes (W. G. Farlow) ; Mystic river marshes. 

 O. Frolichii, Kuetz. 



Newton (W. G. Farlow). 

 O. Froliciiii, Kuetz., var. viridiS, Zeller. 



Medford clay-pits. 

 O. Frolicl-iii, Kuetz., var. ornata, Rab. 



Charles river, Newton. 

 O. princeps, Vauch. 



Cambridge (W. G. Farlow). 



Beggiatoa, Trevis. 



B. alba, Trevis., var. minima, Warming. 



Mystic river salt marshes. 

 B. mirabilis, Cohn. 

 Cambridge, salt marshes ( W. G. Farlow) . 



Leptothrix, Kuetz. 



L. rigidula, Kuetz. 



Mystic river salt marshes. 

 L. subtilissima, Rab. 



Watertown (W. G. Farlow). 



Spirulina, Turpiu. 



S. tenuissima, Kuetz. 

 Everett and Medford, rather common in brackish water; Cam- 

 bridge (W. G. Farlow). 



