Cushman : New England species of Closterium 111 



Length 140-170/*; breadth 15.5-19/*; apices 3.5-4/*; diam- 

 eter of zygospore 40-46 /i. (Plate 3, figures I, 2.) 



New Hampshire : North Woodstock ! 



Massachusetts: Reading, with zygospores ! Lake Watuppa, 



Fall River ! 



*2. Closterium Malmei Borge 



Closterium Malmei Borge, Arkiv for Botanik 1 : 79. pi. 1. f. 21. 



1903. 



Cells of medium size, about six times as long as wide, strongly 

 curved, outer margin an arc of 140 , inner margin not tumid but 

 evenly curved throughout, gradually narrowed to the apices, which 

 are slightly dilated, then suddenly attenuated ; cell-wall reddish- 

 brown in color, with about 10-12 costae visible across the cell. 



Length 250-405 p ; breadth 50-63 [t ; apex 1 1-1 5- 5 l l - (Plate 

 3, figures 4, 5.) 



Massachusetts : East Bridgewater ! Chilmark (H. C, no. 



%)! 



Our specimens seem to be identical with those of Borge, 



described from Paraguay as C. Malmei. 



*3. Closterium Archerianum Cleve 



Closterium Archerianum Cleve, in Lund. Nova Acta Reg. Soc. 



Sci. Upsal. III. 8: 77- pi- 5- /• '3- 1871. — W. & G. S. 

 West, Brit. Desm. 1: 115. pi- U- f-8-io. I9°4- 

 Cells of medium size, about ten times as long as wide, strongly 

 curved, narrowing regularly to the apices ; cell-wall brown witn 



8-10 striae visible across the cell. . 



Length 185-210/i; breadth 19-22//. (Plate 3, figure 3.; 



Massachusetts : Reading ! 



4. Closterium didymotocum Corda 



Closterium didymotocum Corda, Aim. de Carlsbad, 185, 190, 19 2 , 



209. pi. 5 , /. 64, 65. 1835. 

 8. f. 12, 1 j. 1884.— Joh 

 1894. 



5- 1 904. 



pi. 



pi. 12. f. 



Closterium Ensis Cushman, Rhodora 5: 255. I9°3- 

 L Cells large, 9 -i 2 times as long as wide slightly curved apices 

 ^ad, truncated, angles rounded, often sl.ghtly recurved cdl- 

 »aU yellow-brown, ends with a darker annular thickening, smooth 

 0r often delicately striate. 



