1906] Collins,— Notes on Algae,— VII 123 



pointed, free or entangled strings, waving actively in the current. 

 The stipe was dark brown, the lamina and its divisions were intense 

 blue-green; sometimes such a frond had a length of 60 cm., and a very 

 curious resemblance in habit to one of the digitate Laminarias. It 

 was distributed in Collins, Holden & Setchell, Phycotheca Boreali- 

 Americana, No. 1254. 



Lyngbya aestuarii (Mert.) Liebmann and L. semiplena (Ag.) 

 J. Ag., are found as marine algae the world over, except in arctic and 

 antarctic regions; the former has been found occasionally in fresh 

 water in Europe, but apparently not in this country; both grew abun- 

 dantly in an old claypit at West Cambridge, Mass., Aug. 6, 1905. 

 L. aestuarii from this locality has been distributed as P. B.-A., No. 

 1255. 



Calothrix stagnalis Gomont, Journal de Botanique, Vol. IX, 

 p. 197. Forming stellate tufts on various filamentous algae in standing 

 water, Medford, Mass., in August, 1903. It is one of the few dis- 

 tinctly epiphytic species of the genus; the filaments, seldom exceeding 

 a millimeter in length, are 8-10 [x in diameter at the middle, tapering 

 to a fine hair above, somewhat thickened at the decumbent base. 

 The sheath is thin and transparent, the trichome aeruginous, distinctly 

 torulose, with cells about as long as broad. There are two basal 

 heterocysts, yellowish, spherical or subquadrate, and above them, in 

 the mature plant, a sub-cylindrical spore, 12-14 ^ diameter, 2-4 diam- 

 eters long; rarely two spores occur. Spores have been reported as 

 produced under culture in a marine species of Calothrix, but C. stag- 

 nalis was the first in which spores were found under normal condi- 

 tions. Apparently the only record up to the finding of the American 

 locality, as above, is that for the original station near Angers, France. 

 Distributed as P. B.-A., No. 1114. 



Endoderma viridis (Reinke) Lagerheim, Ofversigt Vet. Akad. 

 Forhandl., p. 74, 1883. The only species of Endoderma hitherto 

 known in America is E. Wittrockii (Wille) Lagerh., which is not 

 uncommon in various brown algae on the New England coast. In 

 September, 1883, the writer collected at Falmouth, Mass., a specimen 

 of Seirospora Griffithsiana Harv., and on examining it under the 

 microscope found in the older parts a green endophyte which he could 

 not identify at the moment, and a memorandum was made to look it 

 up when convenient. It was not until the present year that the matter 

 was again taken up; and it was found that the plant agrees with 

 description and figures of E. viridis. The filaments are more slender 



