Semi-Centennial Volume. 159 



50. S. longata Kuetz. Plate III, fig. 16. 

 Kansas: CoflFeyville, October, 1916. 

 Iowa (4); Colorado (15); Mo. (11). 



51. S communi'i Kuetz. 

 Kansas: Horton, June, 1916. 

 Iowa (4). 



52. S. decimina Kuetz. 



Kansas: Horton, June, 1916, masses. 

 Iowa (4); Nebraska (24). 



53. S. crassa Kuetz. 



Kansas: Gardner, June, 1916, great masses. 

 Iowa (4); Colorado (15); Nebraska (25). 



54. S. fluviatilis Hilse. 



Kansas: Paola, November, 1915; July, 1916; masses. 

 Iowa (4); Nebraska (24). 



55. S. quadrata (Hass) Petit. 

 Kansas: Burlingame, October, 1916. 

 Iowa (4); Nebraska (24). 



Family III. Mesocarpace^. 



Chromatophore an axillary plate with two or more pyrenoids. 



Mougeotia. 



56. M. elegantula Whittrock. 



Kansas: Pittsburg, September, 1915. 



57. M. delicatula WoUe. 



Kansas: Douglass; November, 1915; April, 1916; 

 June, 1916. 



58. M. sp.f. 



Kansas: Horton, June, 1916, mixed with Spirogyra 

 and Zygnema. 



59. M. sp.? 



Kansas: Chanute, August, 1916, only a few strands. 



Order II. VOLVOCALES. 



Key to Famdlies of Volvocales. 



1. Cells free, never forming colonies 1. Chlamydomonadacese. 



II. Cells united in colonies. 



* Colonies of various form, cells motile when free, sometimes 



when in colonies 3. Tetrasporacese. 



* * Colonies spherical, ovoid, or disk-shaped; vegetative cells 

 normally always motile 2. Volvocacex. 



Family I. Chlamydomonadack*:. 



Kci) to geiiera of Chlamydovionadojcese. 

 I. Cells spherical or ovoid. 



* Protoplasmic threads passing through the cell wall. 



1. Hseniatococciis. 



* * No protoplasmic threads in cell wall 2. Chlamydomonas. 



1. Haematococcus 



60. H. pi uvialis F\oto-w. (H. lactistric Girod). 

 Kansas: O^awatomie, August, 1915. 

 Nebraska (2) ; Colo. (15). 



I 



