484 Wisconsin Academy of Sciences, Arts, and Letters. 
S. polymorphus. Wood. 
Wood, 1869, p. 135. Wood, 1874, p. 91; PL XI, Fig. 1. Vorce, 
1881, p. 31; PI. VII, Fig. 31. Jones, 1887, p. 115. Wolle, 1887, 
p. 173. de Toni, 1889B, p. 567. Kellermann and Werner, 1893, 
p. 389. Stokes, 1893, p. 51. de Wildermann, 1893A. Balsamo, 
1900, p. 266. Kellermann, 1902, p. 223. 
“Cellulis fusiformibus vel ovatis vel ellipticis vel globosis, 
4-12 y diam. singulis vel 2-7 conjunctis, saepius spina sin¬ 
gula, subinde utrinque biaculeatis; apicibus obtusis, sub- 
acutis vel acutissimis; aculeis gracillimis, valde acutis, 
rigidis, longiusculis.” 
This species of Wood’s is a blanket description of a num¬ 
ber of forms, but the ones most easily recognized from his 
figures are S. quadricauda (Turp.) de Breb. and Ankistro- 
desmus. 
S. bacilaris. Gutw. 
Gutwinski, 1890, p. 63. 
“Cellulae oblongae, utroque polo attenuatae protractae 
et rotundatae. Long. 12 y; lat. 7 y et apic. 2.4 /*.” 
S. bijugatus var. disciformis Chodat. 
Chodat, 1902, p. 213. Migula, 1907, p. 658. Brunnthaler, 
1913, pp. 169, 172. 
S. bijugatus form disciformis. Volk, 1905, p. 64. 
Mention has already been made of the fact that the de¬ 
scription of this variety is so vague that it might mean S. 
bijuga var. irregularis or S. arcuatus var. platydisca. 
S. bijugatus forma verrucosa Teodoresco. 
Teodoresco, 1907, p. 129; Fig. 1. 
Since the arrangment of the granulations on the cell wall 
is not described by Teodoresco the realtionship of this form 
to the others with granulations on their cell walls can not be 
determined. 
