1G EXPLANATION OF THE PLATES. 



PLATE LXX. 



Fig. 1. Microcoleus repcns. — Fig. 2. Microcoleus gracilis. 

 — Fig. 3. Microcoleus anguiformis. — Fig. 4. Oscillatoria 

 cinerea. — Fig. 5. Oscillatoria pulchella. 



PLATE LXXI. 



Fig. 1. Oscillatoria mucosa. — Fig. 2. Oscillatoria limosa. — 

 Fig. 3. Oscillatoria nigra. — Figs. 4. 6. and 7. Oscillatoria 

 contexta. — Fig. 8. Oscillatoria Carmichaeli. — Fig. 5. 

 Oscillatoria spadicea. — Fig. 9. Oscillatoria virescens. — 

 Fig 10. Oscillatoi'ia decorticans /3 corticola. 



PLATE LXXII. 



Fig. 1. Oscillatoria tenuis. — Fig. 2. Oscillatoria atrugescens. 

 Fig. 3. Oscillatoria thermalis. — Fig. 4. Oscillatoria tere- 

 briformis. — Fig. 5. Oscillatoria spadicea. — Fig. 6. Oscil- 

 latoria turfosa. — Fig. 7. Oscillatoria autumnalis. — Fig. 8. 

 Oscillatoria splendida. — Fig. 9. Oscillatoria subfusca. — 

 Fig. 10. Oscillatoria violacea. — Fig. 11. Oscillatoria ru- 

 pestris. — Fig. 12. Oscillatoria muscorum. — Fig. 13. Oscil- 

 latoria Dickiei. — Fig. 14. Lyngbya copulata. 



PLATE LXXIII. 



Fig. 1 . Nostoc macrosporum. Fig. 2. Filaments of the same 

 dividing themselves into separate portions, each of which 

 forms a distinct individual. 



PLATE LXXIV. 



Fig. 1. Nostoc caruleum. — Fig. 2. Nostoc commune. — Fig. 3. 

 Nostoc ? variegatum. — Fig. 4. Nostoc muscorum. 



PLATE LXXV. 



Fie. 1. Trichormus incurvus ? — Fig. 2. Anabaina fios- 

 aqua. — Fig. 3. Anabaina impalpebralis ? — Fig. 4. Ana- 

 baina licheniformis ? — Fig. 5. Spirillum Jenneri. — Fig. 6. 

 Spirillum rupestre. — Fig. 7. Spirillum Thompsons. — Fig. 8. 



