EXPLANATIONS AND REFERENCES, 

 PLATE CLXXXTX. 



Figures magnified 250 diameters. 



PAGE. 

 Fig. 1. SYMPHYOSIPHON CASTELLI, a cluster of filaments, . . 262 



" 2. SYMPHYOSIPHON AMBIGUUM, often intermixed with other algae 



on moist rocks. . . . 262 



" 3. SYMPHYOSIPHON HOFMANNI, a simple cluster; not always so 



spreading, . . . 262 



" 4. SYMPHYOSIPHON BORNETIANUM, from specimens coating old 



bricks, . . .261 



'' 5. SYMPHYOSTPHON AUSTINII, a few filaments separated from an 



almost black stratum, . .261 



" 6. SYMPHYOSIPHON BORETIANUM, from clay cliffs, South Carolina, 261 



" 7. SYMPHYOSIPHON HIRTULUS, the normal growth on damp rocks, 



and moist compact soil, . . 261 



" 8. filaments separated from clusters, 262 



