394 THE MICROSCOPIST. 



* Plants with a frond of colorless gelatinous substance, 

 f Frond amorphous. 



1. Palmella. Frond a slimy stratum, crowded with 

 large globular cells, multiplying by division ; green and 

 red. P. cruenta. 



2. Microhaloa. Frond mucoid, floating in water, 

 crowded with minute cells, multiplying by division ; 

 oreen and red. 



O 



f f Frond definite. 



3. Glceocarpus. Frond of cells in wade gelatinous coats, 

 inclosed in similar coats of parent-cells for several genera- 

 tions. 



4. Botrydina. Frond globose, the periphery of cells co- 

 hering into a sort of cellular epiderm, the inner cells free. 



5. Clathrocystis. Frond gelatinous, first globose, then 

 hollow, then broken by irregular expansion into a coarse 

 net, finally breaking up; frond crowded with minute cells, 

 multiplied by division. 



6. Coccochloris. Frond globose, gelatinous, containing 

 numerous distinct cells, all free. 



7. Merismop&dia. Frond very minute, flat, square, ge- 

 latinous ; cells in families of four, sixteen, and sixty-four. 



8. Urococcus. Frond of streaked gelatinous tubes, 

 formed of ensheathing parent-cell membrane in a single 

 row, with cells solitary or binary (from division) in ends 

 of the tubes. 



9. Hormospora. Frond a wide, gelatinous, simple, or 

 branched sheath, with single row of cells in twos or fours. 



10. Tetraspora. Frond gelatinous, more or less foliace- 

 ous ; cells in fours, ultimately becoming free as zoospores. 



11. Hydrurus. Frond toughly gelatinous, filiform, with 

 imbedded longitudinal rows of cells. 



12. Palmodictyon. Frond gelatinous, filiform, branched ; 

 branches dividing and anastomosing into a net, consisting 

 of large vesicular cells with colored contents, which escape 

 as zoospores. 



