EXPLANATIONS AND REFERENCES, 

 PLATE CXCVIII. 



PAGE. 

 Figs. 1, 2. A NAB JEN A CUPRESSAPHILA, from trunks of cedar trees near 



water's edge, swamp?, New Jersey, 289 



" 3, 4. NODULARIA PALUDOSA, from specimens, Colorado and Pennsyl- 

 vania, .... 291 



" 5,6. A PHANIZOMENON FLOS- AQUAE, short sections with spores, .291 



" 7, 8. " agglutinated filaments, . 291 



" 9, 10. ANABTENA, filaments, one in normal vegetative, moniliform con- 

 dition and the other in process of cell division,286, (298) 



Fig. 11-13. ANAB^NA, three progressive conditions of development, 286, (298) 



" 14-19. AN A EVEN A, advanced stages of growth, . . (286,298) 



" 20-23. ANAB^ENA, FLOS-AQUAE, filaments of type-form, . . 287 



" 24-26. " Var. circinalis, . . .287 



Figs. 27, 28. ANABJENA GIGANTEA, two short sections, . . . 287 



Fig. 29-32. A NAB JEN A VARIABILIS, ..... 287 



" 33-35. SPHAEROZYGA HASSALLII, three filaments, specimens of many 



variable forms, . . . 289 



" 36. OSCILLAEIA, filament resulting from the last, . . . 289 



Figs. 37, 38. SPHAEROZYGA POLYSPERMA, from ponds, pools, etc., . 289 



" 39, 40. ANAB^ENA OSCILLARIOIDES, filaments in different stages of de- 

 velopment, . . . 288 



