Cushman f New England species of Closterium 133 



Cells with shorter and less attenuated apices. 

 Massachusetts : Amherst ( W. West). 



49. Closterium setaceum Ehrenb. 



Closterium setaceum Ehrenb. Infus. 97. pi. 6. f. p. 1838. 

 Wolle, Desm. U. S. 47. pi. 8. f. 6, 7, p-n. 1884. — W. & 



West 



pi. 26. f. 9-13. I9°4- 



Cells small, very slender, nearly straight, 35-45 * imes as lon S 

 as wide, median portion fusiform, both margins equally convex, 

 extremities prolonged, very slender ; cell-wall colorless or slightly 

 yellowish-brown, with about 12 or 13 fine striations across the 

 surface ; zygospore cruciform. 



Length 235-465 /u ; breadth 6-10// ; apices 1-2.3 //. (Plate 



4, FIGURES 15, l6.) 



I 



Maine : Spencer Pond, East Middlese 



New Hampshire : Pudding Pond, North Conway ! 



Massachusetts : Near Salem (Bailey) 



\ 



Bridgewater, 

 Nantucket ! 



Watuppa, Fall River! 



Rhode Island: Providence (Bailey); Nyatt ! 



The following forms of Closterium are not included in the 



above records : 



r _. M 



" Closterium decussatum Kg. 



Mt 



Mount Washington, Mass. What Wolle had is a perplexing 

 thing, as I collected in Gilder Pond in 1907 and failed to find any- 



Wolle 



>,„ t 



that locality. 



Closterium nasutum Nordst. 



Mountains, Mas 



sachusetts." I have failed to find anything corresponding to this 



species. 



Closterium sudangustatum West 



This was described from Maine, " Bog between Orono and 

 Bangor." It is close to some forms of C. aHgustatum, var. clav- 

 *tnm Hastings. 



Boston Society of Natural History. 



Explanation of plates 3 5 



Platk 3 



Fig. i. Closterium Cynthia De Not. X 45°- 

 a 2 <« ii « zygospore, X 45° 



