long, sharply pointed apex which is one-half or more the length of 

 the cell; lorica ll-13.3ju, in diameter, 60-105/x long. 

 Euplankter. Mich. 



HYALOBRYON Lauterborn 1896, p. 17 



Solitary or colonial, epiphytic, the protoplast housed in a cone- 

 shaped lorica which is composed of a series of nesting cups repre- 

 senting growth stages, the margin of the cups forming lateral pro- 

 jections or barbs; protoplast with 2 elongate chromatophores. 



Hyalobryon mucicola ( Lemm. ) Pascher in 

 Pascher & Lemmermann 1913, p. 81 



PL 98, Figs. 11, 12 



Lorica conical, cylindrical in the midregion, with an expanded 

 mouth, tapering posteriorly to form a short stipe which attaches 

 the envelope to the gelatinous investment of various algae, margins 

 of the lorica showing several apiculations marking the zones of 

 growth; lorica 4-6/i, in diameter, 24-45/x long. 



Rare to common in a number of lakes and swamps. Wis. 



UROGLENOPSIS Lemmermann 1899a, p. 107 

 A free-swimming sphere with hundreds of spherical or ellipsoidal 

 cells arranged at the periphery of the colonial gelatinous envelope; 

 cells with 1 or 2 brownish, parietal, plate-like or disc-like chromato- 

 phores; flagella 2, of unequal length, attached in the narrowed 

 anterior end of the cell and extending through and beyond the 

 colonial mucilage; pigment-spot sometimes present in the anterior 

 portion of the cell. 



Uroglenopsis americana ( Calkins ) Lemmermann 1899a, p. 107 



PI. 99, Figs. 1-5 



A free-swimming, spherical colony with hundreds of ellipsoid or 

 ovoid cells evenly distributed within the periphery of the gelatinous 

 investment; cells with 1 parietal, plate-like chromatophore; 2 flagella 

 of unequal length and a pigment-spot; cells 3-7 /x in diameter; colony 

 500/A in diameter. 



This is a fairly common component of the plankton in a large 

 number of lakes, apparently preferring hard water; especially abun- 

 dant during late summer. Mich., Wis. 



ORDER RHIZOCHRYSIDALES 



This small order includes those members of the Chrysophyceae 

 which are essentially rhizopodal, although a few may have a tran- 



[380] 



