114 Cushman: New England species of Closteri 



UM 



is difficult to determine. 



Mt 



Massach 



Collections which I made there in May, 1907, 



failed to show anything which might suggest these forms. 



8. Closterium costatum Corda 



pi- 5- /• 



6i-6 3 . 1834.— Wolle, Desm. U. S. 42. pi. 6. f. i 9 . 1884. 



W. & G. S. West, Brit. Desm. 1 : 1 20. pi. 13. f. 1-3. 

 1 904. 



Cells of medium size, 7-9 times as long as wide, moderately 

 curved, apices rounded ; cell-wall dark yellowish-brown, with 6-8 

 costae visible across the cell. 



Length 215-410/^; breadth 29-44 /'• (Plate 3, figure i 3.) 

 Maine: Orono (W. West). 



New Hampshire : Pudding Pond, North Conway ! Intervale ! 



Massachusetts: Amherst (W. West)- Tewksbury {Lager- 

 heim) ; Lake Quinsigamond, Worcester {Stone) ; Reading ! West 

 Bridgewater ! Gay Head ! Almanac Pond, Nantucket I 



8a. Closterium costatum Westii Cushman 

 Closterium costatum Corda, forma, W. & G. S. West, Trans. Linn. 



Soc. Bot. II. 5 : 237. pL i 3 . / 23 , 24. 1896. 

 Closterium costatum Westii Cushman, Rhodora 7:114. 1905. 



rt, Ce {h onl y sli ghtly curved, smaller than the typical, tumid in 

 tne middle, apices truncate ; cell-membrane punctate between the 



Length 230-300 (i ; breadth 25-32 // ; apices 10-1 2 ft. (Plate 



New 



) 



C 



Massachusetts : Gay Head, Marthas Vineyard ! 



9. Closterium regulare Breb. 



Closterium regulare Breb. Mem. Soc. Sci. Nat. Cherbourg 4 > 

 148. pi. 2. f. 3 - 5 . l85 6._W. & G. S. West, Brit. Desm. 

 I: 122. pl.ij.f. 4 -6. 1904. 

 Cells of medium size, 7-9 times as long as wide, moderately 



vpIU ' if P K CeS truncateJ y or angularly rounded ; cell-wall light 

 yellowish brown, with 10-12 costae visible across the cell. 



N? Tn^tf '' breadth 25 "37/^ apices 6. 5 -9-5/<- 



