164 MIDDLESEX FLORA. 



M. terrestris, Desmaz. 



Newton (W. G. Farlow) ; 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. Frolichii, Kuetz., var. viridis, Zeller. 



Medford clay-pits. 

 O. Frolichii, 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, Turpin. 



S. tenuissima, Kuetz. 



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

 bridge (W. G. Farlow). 



