488 Wisconsin Academy of Sciences , Arts , and Letters. 
S. costatus var. poriferus Gutwinski. 
Gutwinski, 1909, p. 435; PI. VII, Fig. 5. 
Is Coelastrum Bohlinii Schmidle and Senn. 
S. obliquus var. inermis Playfair. 
Playfair, 1912, p. 518; PL LVI, Fig. 9. 
The shape of the cells differ from that of Scenedesmus , 
but so crude is Playfair’s drawing that it is impossible to 
determine just what alga it is. 
S. chlorelloides Chodat. 
Chodat, 1913, p. 45; Fig. 23. 
The alga is much more closely related to Palmellococcus 
than to Scenedesmus. 
S. wisconsinensis (Smith) Chodat. 
Chodat, 1913, p. 50; Figs. 35-37. 
Tetradesmus wisconsinensis. Smith, 1913, p. 76; PL I, Figs. 2-20. 
The constant occurrence of the cells in two parallel series 
excludes this species from the genus Scenedesmus. 
SPECIES KNOWN IN NAME ONLY 
S. apiculatus Corda. 
de Toni, 1889B, p. 567. 
Scenodesmus caudatus var. apiculatus. Kiitzing, 1849, p. 186. 
S. ellipticus Corda. 
de Brebisson, 1839, p. 271. 
S. lacustris (?) 
Bachmann, 1908, p. 44. 
