126 Cushman : New England species of Closterium 



Length 1 70-294 /i; breadth 13-16//. 



Maine : Orono {Harvey). 



New Hampshire: Pudding Pond, North Conway! 



Massachusetts: Amherst (W. West)] Winchester! 



33. Closterium gracile Breb. 



Closterium gracile Breb. in Cheval. Microscop. 272. 1839. 

 Wolle, Desm. U. S. 39. pi. 6. f. 4, 5. 1884. — W. & G. S. 

 West, Brit. Desm. 1: 166. //. 21. f. 8-12. 1904. 



C. subtile Harvey, Bull. Torrey Club 19: 121. 1892. — Cush- 

 man, Rhodora 5 : 252. 1903. 



Cells small, linear, about 40 times as long as wide, median 

 portion straight with parallel margins, ends gradually attenuated 

 and somewhat curved, apices obtuse ; cell-wall colorless and 

 smooth. 



Length 172-264/*; breadth 5-6.2//; apices 2.8 ft. 

 Maine : Orono ( W. West, Harvey). 



Massachusetts : Lake Watuppa, Fall River ! Misery Island, 

 off Beverly ! 



Rhode Island : Nyatt ! 



*33«- 



West 



Closterium gracile var. elongatum W. & G. S. West, Brit. Desm. 



1 : 168. pi. 21. f. 14-16. 1904. 



Cells very elongate, over 100 times as long as wide, otherwise 

 much like the typical. 



Length 3 5 5 fi • breadth 3.2 n ; apices 1.8/1. 



Massachusetts : Cedar Pond, North Falmouth ! 



* 33^. Closterium gracile tenue (Lemm.) W. & G. S. West 

 Closterium limneticum Lemm., var. tenue Lemm. Phytoplankton 



Sachsis. Teiche 28. //. 2. f. 42-4.4.. 1899. 

 C. gracile, var. tenue W. & G. S. West, Trans. Linn. Soc. Bot. II. 



6 : 138. pi. 18. f. 22, 23. 1902 ; Brit. Desm. I : 168. //• 21- 



f. 13. 1904. 



Cells smaller and more slender than in the typical form of the 

 species. 



Length 78 /1 ; breadth 3 //. 



Massachusetts : Reading ! 



