6 



B Cellulee in familias evidentiores consoeiatse, tegumento communi circumlusse. 



a Familise amorphse. 



1. Tegumenta crassa per divisiones multas perdurantia, tegumenta nova cir- 

 cumdantia. 



a Oellulee sphsericse. 



Glceocajysa Kuetz. — Stratus expansus, amorphus. 



Entophysalis Kuetz. — Stratus crustaceus verrucosus, cellulis in series breves 



ordinatis. 

 Chondrocystis Lemmerm. — Stratus lobosus, tegumentis imo latere crassioribus. 

 Placoma Schousb. — Stratus cavernosus, cellulis quaternatis. 



p Cellulse elongatse (nec sphaericae). 



Gloeothece Naeg. — Cellulse chromatophoro inconspicuo, tegumento crasso. 

 Rhabdoderma Schm. et Laut. — Cellulse chromatoplioro inconspicuo, tegumento 



tenui (familiae e cellulis uniseriatim dispositis constitutse). 

 Zachariasia Lemmerm. — Cellulse chromatophoro stellseformi, intra tegumentum 



amplum quaternse. 



2. Cellulae tegumentis secundariis carentes; membranse secundai-ise omnes 

 diiiiuentes, 



Aphanocapsa Naeg. — Cellulse subsphgericse ; multiplicatio secus omnes dire- 



ctiones. 

 Aphanothece Naeg. — Cellulse elongatee; multiplicatio tantum divisione trans- 



versa. 



6 Familise forma definita characteristice constitutse. 

 a Libere natantes. 



1. Cellulse in stratibus compluribus ordinatse. 



Microcystis Kuetz. — Cellulae rotundse globosse aut racemosse; familiae non 



clathratse. 

 Planosphcerula Borzi. — Cellulse globosse vel breviter ovatse ; familise paucicel- 



lulares globosse, motu lentissimo donatse. 

 Clathrocystis Henfr. — Cellulse rotundatae; familise clathratse. 

 Marssoniella Lemm. — Cellulse piriformes; familige csespitoso-radiatse. 

 GomphosphcBria Kuetz. — Cellulae saltem pro parte cuneatse ; familiee sphsericae. 



2. Cellulse in stratu unico ordinatse. 



Ccelosphcerium Naeg. — Familise sphserieo-excavatee ; tegumenta secundaria 



inconspicua, cellulis rotundatis. 

 Ccelosphceriojysis Lemmerm. — Familise sphserico-excavatae ; tegumenta secun- 



daria evidentia, cellulis rotundatis. 

 Pilgeria Schmidle. — Familise sphserioo-excavatse, cellulis polyhedricis. 

 Merismopedium Meyen. — Familise tabulares vel pelliculares ; cellulse snbsphse- 



ric8e vel elongatse. 



