Cushman : New England species of Closterium 125 





curved, median portion nearly straight, ends more curved, gradu- 

 ally attenuated to the broadly truncate apices ; cell-wall colorless 

 or slightly yellowish-brown, smooth. 



Length 84-200/4; breadth 12. 5- 15. 5// ; apices 6 p.. 



Maine: Orono (W. West). 



New Hampshire : Holderness, frequent [Johnson). 



Massachusetts: Gibbs Pond, Nantucket! 



* 30. Closterium Toxon West 



Closterium toxon West, Jour. Linn. Soc. Bot. 19: 121. //. /p. f. 

 14. 1892. — W. & G. S. West, Brit. Desm. 1: 160. pi. 20. 



f. 13, 14. 1904. 



Cells linear, 25 or more times as long as wide, straight with 

 nearly parallel margins, except toward the ends, which are slightly 

 curved, apices subtruncate ; cell-wall colorless or a light yellowish- 

 brown, smooth. 



Length 242-365 ft; breadth 9-12/1; apices 4.5-8 ft. (Plate 

 4, figure 17.) 



Massachusetts: Lake Watuppa, Fall River! Cedar Pond, 

 North Falmouth ! 



*3i. Closterium praelongum Breb. 



Closterium praelongum Breb. /. c. 152. pi. 2. f. 41. 1856. 



Wolle(?), F.-W. Alg. U. S. 24. pi. 55- /• z 5> '<$■ l88 7- 

 Desm. U. S. 43. pi. 6. f. 15, 16. 1892. — W. & G. S. West 

 Brit. Desm. 1: 164. //. 21. f. /, 2. 1904. 



Cell 



5 



curved, inner margin slightly concave for its entire length, gradu- 

 ally attenuated to the somewhat recurved ends, apices obtuse; 

 cell-wall colorless, smooth. 



Length 520//; breadth 14/i; apex $ft. 



Massachusetts : Lake Watuppa, Fall River ! 



Wolle figures a striate form with colored cell-wall under this 

 name. The breadth given is rather large also for this species. 



32. Closterium strigosum Breb. 



Closterium strigosum Breb. /. c. 153- P L 2 - / 4-3- 1856. — Wolle, 

 Desm. U. S. 42. pi. 6. f. ij, H- P L S3- /• ?> "»• l884 " 

 W. & G. S. West, Brit. Desm. 1 : 165. /'• **- / * 7- I9<H- 

 Cells of medium size, 12-18 times as long as wjd£ shghtly 



cu .«-ved, nearly straight in the middle with the ends more curved, 



a Pices subacute ; cell-wall colorless, smooth. 



