bearing 2 vase-like or collar-like extensions through which a long, 

 straight rigid seta projects; 1 flagellum arising from between the two 

 sheathed setae; chromatophores 2, parietal, golden-brown. 



Chrysosphaerella longisphia Lauterborn 1896, p. 16 



PI. 98, Fig. 1 

 Characteristics as described for the genus; cells 9/x in diameter, 

 15/i, long; colony up to 250/* in diameter. 



Common in the plankton of a variety of lakes; also in Sphagnum 

 bogs, roadside ditches, etc.; frequently accompanies Synura uvelh.. 



Suborder Isochrysidineae 



In this group the organisms may be unicellular or colonial, attached 

 or free-swimming. In any case the cells are equipped with 2 llagella 

 of equal length but are difficult of discerimient in the sedentary 

 forms. There are 2 elongate, brown chromatophores. 



Key to the Families 



Cell membrane smooth; plants with or without a lorica 



(unicellular and possessing a lorica in our specimens) syncryptaceae 



Cell membrane with silicious scales which are inconspicuous 



except at the anterior end of the cells, where they form barbs 



( plant a globose colony in our specimens ) - SYNtmACEAE 



FAMILY SYNCRYPTACEAE 



Cells in this family have smooth membranes. Although equipped 

 with 2 flagella of equal length, some organisms are sedentary and 

 inclosed in a lorica. Syncrypta volvox Ehrenb., a colonial form, has 

 been reported from Michigan (Gustafson, 1942). 



DEREPYXIS Stokes 1885, p. 317 



Attached; protoplasts inclosed in a vase-like or flask-shaped lorica 

 which usually has a short pedicel and is narrowed anteriorly to form 

 a long or short neck through which 2 long flagella emerge; protoplast 

 globose or hemispherical, suspended from the sides of the lorica by 

 protoplasmic strands, and usually resting on a cross membrane 

 through the median part of the envelope; chromatophores 1 or 2, 

 brown, plate-like. 



This genus should be compared with Lagynion. 



Key to the Species 



Lorica vase-shaped, abruptly parrowed anteriorly 



to a slender neck; sessile.— — ^- dispar 



Lorica elongate-ellipsoid, narrowed gradually 



anteriorly to a wide neck; short-stalked D. amphora 



[374] 



