186 ILLINOIS BIOLOGICAL MONOGRAPHS [424 



14(11) Faint concentric striations; pointed at sides and middle part of posterior margin; 

 polar capsules unequal in size; length 7 to 8/x, breadth 6 to In, thickness 5/t 



Sphaerospora angulata Fujita 1912 (102) 



Incompletely described species 



Sphaerospora sp. Davis 1917 (103) 



Sphaerospora sp. Southwell et Prashad 1918 (103) 



Genus SINUOLINEA Davis 1917 



1(4) Spore with two processes 2 



2( 3) Processes lateral and long (20)u); spore: 9 to 11^ long, 9/i broad, process 18 to 

 llfi long 



Sinuolinea hrachiophora Davis 1917 (106) 



3( 2) Processes posteriad from sides and short; diameter 12 to 13^. Trophozoite 

 opaque 



Sinuolinea opacita Davis 1917 (106) 



4( 1) Spore without process 5 



5( 6) Trophozoite with active amoeboid movements. Spore: sutural ridge S-shaped 

 at anterior part; length 15^, breadth 12;x, thickness 8^ 



Sinuolinea arborescens Davis 1917 (105) 



6( 5) Trophozoite with slow amoeboid movements 7 



7(8) Sutural plane much twisted on its axis; capsulogenous cells large occupying more 

 than half of sporal cavity; polar capsules opening on opposite sides; diameter 

 12 to 14ax 



Sinuolinea capsularis Davis 1917 (lOS) 



8( 7) Sutural plane not much twisted; diameter 15/* 



Sinuolinea dimorpha Davis 1916 (104) 



Genus MYXIDIUM ButschU 1882 



1(16) Breadth of spore equal to or more than half of length 2 



2( 7) Shell-valves unstriated 3 



3( 6) Sutural plane curved into an S 4 



4( 5) Spore small; length 8 to 12|t, breadth 4 to 6/x 



Myxidium incurvatum Thelohan 1892 (108) 



5( 4) Spore large; much broader; length 20.8 to 23.4/t, breadth 13 to 15.6|i 



Myxidium inflalum Auerbach 1909 (HI) 



6( 3) Sutural plane straight; spore cylindrical; surrounded by a gelatinous envelope; 



length 10 to ll/x, breadth 6/i 



Myxidium glulinosum Davis 1917 (115) 



7( 2) Shell-valves striated 8 



8( 9) Sutural line curved into an S; form oval; circular in cross-section; openings of 



polar capsules pointed; length 11 to 13m, breadth 8 to 9n 



Myxidium oviforme Parisi 1912 (114) 



9( 8) Sutural line straight 10 



10(13) Sutural line coincides with longitudinal axis of spore 11 



11(12) Sutural ridge distinct; extremities mucronate; length 9 to 10/u, breadth 5 to 5 . 6^, 



thickness 4 . 75 to Sjit. Vegetative form produces cysts, 800 to 900^ in diameter 



Myxidium giardi Cepede 1906 (HO) 



12(11) Sutural ridge faintly marked; extremities gradually drawn out; length 11m, 



breadth 8m. Trophozoite large and leaf-like; diameter up to 1 .35 mm. 



Myxidium phyllium Davis 1917 (116) 



Numbers enclosed in parentheses refer to the page of the article on which is found the description of the species 

 named. 



