Cushman : New England Saccodermae 349 



Sandwich ! Marthas Vineyard ! Nantucket ! R. I. : Nyatt ! Ports- 

 mouth ! Wainskut Pond, North Providence (Bailey). Conn. : 

 Bridgeport ! 



This seems to be the most abundant and widely distributed of 

 the New England desmids, a representative gathering which does 

 not include it being the exception. Its size is extremely variable 

 as shown above. 



*i8. Netrium Naegelii (Breb.) W. & G. S. West. Penium 

 Naegelii Breb. in Pritchard, Infusoria 751. 1861. — Netrium 

 Ndgelii W. & G. S. West, Brit. Desm. i: 66. pi. 7. /. 4, 5. 1904- 



Cells oblong-lanceolate, 4-5 times as long as wide, the apices 

 truncately rounded ; chloroplasts as in the preceding species. 

 Length 100-150/*: breadth 24-28//. 



Mass. : Plainville ! North Watuppa Lake, Fall River ! 

 This species, although a very cosmopolitan one, has not pre- 

 viously been reported from North America. 



19. Netrium oblongum (DeBary) Lutkem. Penium oblongum 

 DeBary, Conj. 42, 73. pi. jG. /. /. 2. 1858. — Netrium ob- 

 longum Lutkem. Beitr. Biol. Pfl. 8: 407. 1902. 



Cells oblong-cylindrical, 3-3^ times as long as wide, the 



apices rounded ; chloroplasts of the usual type, with six longi- 

 tudinal plates. 



Length 96 fi: breadth 29//. 



N. H. : Intervale ! Mass. : Amherst (IV. West). 

 Wolle's figure of Penium oblongum is not this species, but rep- 

 resents a Mesotaenium, possibly M. DeGreyi Turn. 



Netrium oblongum cylindricum W. & G. S. West, Jour. Bot. 



41 : 40. pL 446. f. 10. 1903. 



" Cells smaller than in the typical form and exactly cylin- 

 drical : apices hemispherical." 



Length 60-71 a : breadth 18-22 ft. 



N. H. : Mt. Moosilauke ! 



Netrium oblongum f. major (Turn.) Cushman, Rhodora 7 : 113. 

 1905. 



Cells much larger than in the typical form of the species. 

 Length 168//: breadth 44 ft. 



N. H. : Pudding Pond, North Conway ! 



