SPIROGYRA 171 



formed by both gametangia; fertile cells cylindrlc; zygospores broadly 

 ellipsoid, 57-58 /x x 69-71 /x; median spore wall smooth. 

 South Africa, Angola, July, 1854. 



78. Spirogyra parvispora Wood 1869. Proc. Amer. Phil. Soc. H, 



p. 139. 1872. Smithson. Contribu. Knowledge. 19, p. 169, 



PI. 15, Fig. 7. 



Vegetative cells about y^p- x 150-300 ft, with plane end walls; 4 



chromatophores, making 1.5 turns; conjugation scalariform; tubes 



formed by both gametangia; fertile cells not inflated; spores ellipsoid, 



50 ft X 75-100 /(a; median spore wall brown, smooth. (PL XXVI, Fig. 16.) 



United States: Florida. 



79. Spirogyra turfosa Gay 1884. Essai Monogr. Conjug., p. 187, 



PI. 4, Fig. 3. 



Vegetative cells 68-78^1 x 68-350^4, with plane end walls; 3-4 chro- 

 matophores, making 1.5 to 4 turns; fertile cells cylindric; conjugation 

 scalariform; tubes formed by both gametangia; zygospores ellipsoid, 

 pointed, 65-78/11, x 120-140^4; median spore wall smooth, yellow. (PI. 

 XXVI, Fig. 17.) 



United States: Kansas; Mississippi; Alabama. 



Galicia. 



In the 3 collections from the United States this species was associated 

 with 5. rivularis, which it resembles in all characteristics except size. It 

 would be interesting to know the relative chromosome complements of these 

 2 species. It might be a mutation from S. rivularis due to a single gene 

 change. 



80. Spirogyra nitida (Dillwyn) Link 1833. Handbttch, Pt. 3, 



p. 262. 



Vegetative cells 70-80 ft x 90-300 ft, with plane end walls; 3-5 chro- 

 matophores, making .5 to 1.5 turns; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells cyUndric or enlarged; zygo- 

 spores eUipsoid, rarely somewhat ovoid, 60-76 ft x 90-177 ft; median 

 spore wall brown, smooth. (PI. XXVII, Figs. 1-2.) 



United States: Many records from Iowa and Wisconsin to Massachu- 

 setts, south to Mississippi and Florida. 



Europe; India; Australia; China; South Africa. 



This species consists of many overlapping forms that differ only slightly 

 in dimensions, hence the spread in cell diameters. Near Starkville, Missis- 

 sippi, I found this species hybridizing with S. crassa. In the undrained pond 

 there were also the resulting hybrid segregates. 



81. Spirogyra hymerae Britton & Smith 1942. Ohio Jour. Sci. 



42, p. 70. 



