122 Cushman : New England species of Closterium 



Wolle, Desm. U. S. 41. pi. 6. f. 7, //. //. <?./. 17. 1884. 

 — W. & G. S. West, Brit. Desm. 1: 146. //. 18. f. 2-5. 

 1904. 



Cells large, elongate, only slightly curved, about 10-12 times 

 as long as wide, gradually tapering to the narrow rounded-truncate 

 apices ; cell-wall usually colorless and smooth but in old specimens 

 the cell-wall becomes brownish, sometimes finely striate and the 

 apices thickened just back from the tips. 



Length 3 5 5-480 /i ; breadth 33-42 //. 



Maine : Orono (Harvey, IV. West) ; Mud Pond, Township 6, 

 Range 12 ! 



New Hampshire: Intervale! 



Massachusetts: Lake Quinsigamond, Worcester {Stone); 

 Tewksbury {Lagerheim) ; Stony Brook, Weston ! Carvers Pond, 

 Bridgevvater ! Eastham ! 



24^. Closterium acerosum elongatum Breb. 

 Closterium acerosum, var. elongatum Breb. /. c. 152. 1856. — W. 

 & G. S. West, Brit. Desm. 1 : 148. //. 18. f. 1. 1904. 



Longer and larger than the typical form ; cell-wall yellowish- 

 brown with more distinct striations. 



Length 500-651//; breadth 37-54 ft. (Plate 4, figure 6.) 



Massachusetts : Amherst ( W. West) ; Medford ! Lake 



Watuppa, Fall River ! Nantucket ! 



' 



25. Closterium lanceolatum Kiitz. 



Closterium lanceolatum Kiitz. Phyc. Germ. 130. 1845. — Wolle, 

 Desm. U. S. 39. pi. 8. f. 14. 1884. — W. & G. S. West, 

 Brit. Desm. 1 : 149. pi. i 7 . /. p, 10.pl. 18. f. 7. I9°4- 

 Cells large 4^-7 times as long as wide, nearly straight, outer 

 margin slightly curved, inner margin often slightly convex, gradu- 

 ally attenuated to the acutely rounded apices ; cell-wall colorless, 

 smooth. 



Length 390-41 5 /i ; breadth 70-93 fx. 



\ 



Vermont : Lake Champlain ! 



Massachusetts: Amherst {W. West); South Framingham 



Rhode Island : Nyatt ! 



26. Closterium Lunula (Mull.) Nitzsch 



Vibrio Lunula Mull. Naturforsch. 20: 142. 1784. 



Closterium Lunula Nitzsch, Neue Schrift. Nat. Gesells. Halle 3 : 60, 





