Simplest Forms of Life. 229 



Palmodictyon viride, Ktz. Not common. 

 * Tetraspora gelatinosa, Ag. Common, 



[* T. lubrica, Ag. Thallus tubular or expanded, simple or branched, 

 often perforated, cells globose, bright green, single, in pairs or fours, 

 probably the same as T. gclaiinosa. 



*T. bullosa, Ag. Thallus saccate or expanded, obovate, i- 6 inches 

 long, verrucose, cells in twos or fours, crowded, granular.] 



Palmella uvaformis, Ktz., and P. f?iucosa, Ktz. Fixed, upon 

 objects under water ; P. botryoidcs, Lgb., and P. heterospora, 

 Rb., form green coatings on window panes ; P. mirifica, 

 Rbh., peach-blossom colored patches upon milk, meat, 

 etc. ; P. prodigiosa, Breb. {Monas prodigiosa, Eh.), on boiled 

 potatoes, rice, bread, etc. 

 [*/•. Jesenii, Wood. Thallus indefinitely expanded, first soft and 

 pellucid, then tubercular, deep olive-green ; cells globose or elliptical. 



*P. dura. Wood. Thallus irregularly sub-globose, irregularly 

 minutely lobate or warty, bluish-black, crustaceous, minute. 



*/•. hyalina, Lgb. Fronds %-\ inch in diameter, globose, ovate or 

 cylindrical ; gelatinous, pellucid, watery, granules numerous, globose, 

 green.] 



'^Porphyridium cruentum, Ng., blood colored gelatin upon moist 

 ground. 

 [The occurrence of this species in this country- is doubtful. 

 *P. magnificum. Wood. Cells globose or sub-globose, often poly- 

 gonal and conjoined into indefinite mass ; purple, granulated, cell 

 wall thick, not laminate.] 



* Raphidium polymorphum, Ktz. Sheave-like, or radiating bun- 

 dles of needle-shaped cells, in ditches, swamps, and par- 

 ticularly in aquaria. 

 JDimorphococcus lunatus^ A. Br. In swamps. 



Pleurococcus vulgaris, Mengh. Forms green, crusty coatings on 

 moist objects ; P. roseo-pcrsicinus, Rh., red coatings. 

 [*/*, seriatus. Wood. Grows on bark ; reddish brown, powdery mass. 

 *P. pulvereus. Wood. Cells very small bluish-green, oval or angular, 

 in families ; pulverulent, bright green. 



Genus. Pagerogalia, Wood. Thallus solid, indefinite, gelatinous, 

 whitish, pellucid, composed of closely aggregated modules, often indis- 

 tinct. Cells globose, crowded. Families surrounded by a thin mem- 

 branous coat and placed in the center of the gelatinous nodule. 

 */*. stillio, Wood. Frond ]A, inch. Cells 4-3000 — 1-2000.J 

 The Palmellaceae are, by many algologists, placed as a third 

 family of the Volvocineae, which I have placed among the 

 Flagellata (Infusoria), according to Stein, Carus, and others. 



