1923] 



MOORE AND CARTER — ALGAE FROM NORTH DAKOTA LAKES 419 



thallus is particularly lax. The basal creeping portion of the 

 thallus is the more important in this species and the upright 

 branches are very scanty in their development. Stigeoclonium 

 sp. Mobius agrees with our species rather better than St. farctum 

 in its relatively short erect filaments. Mobius, however, in de- 

 scribing his species states that in isolated cases these were observed 

 to end in a hair. This seems to imply that hairs were of compara- 

 tively rare occurrence, whereas, on the other hand, our specimens 

 were provided with numerous hairs. Taking all these things 

 into account the alga under consideration seems to have greater 

 affinities with St. farctum Berth., of which it is probably a form 

 with poorer development of the erect part of the thallus. 



Family Herposteiraceae 

 Genus herposteiron Nag. 



Herposteiron confer vi cola Nag. ( = Aphanochaete repens A 



Br.). 



Spiritwood I, Bay; North Twin Lake, near Wing. 



Order SIPHONOCLADIALES 



Family Cladophoraceae 



Genus rhizoclonium Kiitz. 



Rhizoc Ionium crispum Kiitz. 



Wheeler's Pond, I. 



Rh. hieroglyphicum (Ag.) Kutz. 



Wheeler's Pond; Lake P; Lake N; Long Lake, near Binford; 

 Lake Etta; Painted Woods Lake. 



Genus cladophora Kiitz. 



Cladophora Kuetzingiana Grun. 



i 



Spring Lake; Lake O; Lamoreau Lake; Lake N. 



Cladophora sp. 



Cut-off Pond, Stump Lake; Fort Totten Lake; Gravel Lake; 

 Lamoreau Lake; Odessa, I; Lake P; Lake A; Odessa, H; Dion 

 Lake; Strawberry Lake; Alkaline Lake, II; North Twin Lake, 

 near Wing ; Painted Woods Lake ; Lake ; Stump Lake ; Lake P. 



