EXPLANATIONS AND REFERENCES, 



PLATE CXCII. 



Figures magnified 250 diameters. 



PAGE. 

 Figs. 1, 2. SIROSIPHON COMPACTUS, several characteristic filaments, . 271 



Fig. 3-5. SIROSIPHON SCYTONEMATOIDES, . . . 27 1 



" b'. " " macrogonidia, . . .271 



'' 7-8. HAPALOSIPHON ? ...... 



" 9-12. SIROSIPHON CORALLOIDES, Var. injiatus, specimens from Mt. 



Mansfield, Vermont. . . 270 



