The Myxomycetes of the Miami Valley, Ohio. 



159 



ORDER IL COLUMELLIFERAE, 



SUB-ORDER 3. STEMONITAH. 

 SUB-ORDER 4. LAMPRODERMAE. 



ORDER IIL LITHODERMEAE. 



SUB-ORDER 5. DIDYMEAE. 

 SUB-ORDER 6. PHYSARAE. 



ORDER IV. CALOTRICHEAE. 



SUB-ORDER 7. TRICHEAE. 

 SUB-ORDER 8. ARCYRIAE. 



We present in the following pages a synopsis of the orders 

 and genera of the Myxomycetes of North America so far as 

 known, under four sections — Peritrichiae, Calonemata, Col- 

 umelliferae and Calcareae. This is preceded by two analytic 

 tables leading to the genera as numbered in the synopsis. 



TABLE L 



SPORANGIA COMBINED INTO AN AETHALIUM. 



a. Aethalium containing lime, (b.) 

 Aethalium containing no lime, (c.) 



b. Lime in the form of minute roundish granules. 37. 

 Lime in the form of minute stellate crystals. 27. 



c. Aethalium effused with a plane surface, (d.) 

 Aethalium pulvinate or subglobose. (e.) 



d. Walls of the sporangia a thin persistent membrane. 2. 

 Walls of the sporangia with a persistent apex and six 



slender threads. 6. 



e. Thin membranes and slender fibers intermingled with 



the spores, (f.) 

 Slender warted tubules intermingled with the spores. 9. 



f. Fibers bearing small membranaceous vesicles. 5. 

 Fibers not bearing any vesicles. 4. 



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