12 



sporangia borne in short, very numerous, straight or slightly 

 falcate branches which diverge at right angles from the fila- 

 ments, sessile, linear, 60 to 80 fx long by 6 to 7 // broad, gen- 

 erally simple, occasionally pinnate. 



On fronds of Laminari(E, Nahant, Mass. Mrs. R. S. Eigen- 



mann. 



This species,which forms short and dense patches on old Lam- 

 inari(2^ sometimes covering several inches, is evidently closely 

 related to E, tomentosus, and it might be questioned whether it 

 is not a young state of that species. Such cannot well be the 

 case, for the specimens on which the species is founded were 



r 



covered with the very abundant sporangia which indicate matur- 



■ 



ity. E, tomeniosus forms characteristic rope-like masses several 

 inches long, whereas the present species is not over a quarter of 

 an inch long, and extends indefinitely over patches of consider- 

 able extent. Furthermore the filaments are from a quarter to a 

 third narrower than in E, tomentosiis and, although the sporan- 

 gia are much like those of that species in some respects, they are 

 in no instance recurved in the way so common in the sporangia 

 of E. tomeniosus. 



EXPLANATION OF FIGURES. 



Plate LS5XVII. 



I. DidyosipJwn Macounii. Natural size. 



2. Alesogiaia Anderso7tii.B. Unilocular sporangia. A. Base of hyaline hair, x 500. 



Choreocolax 



X 500. 



4. Eciocarpus tomentosoides, showing trichosporangia. x 500. 



Plate LXXXVnL 



5, 6, 9, 10, Gla:osiphonia verticillaris . 9, A plant of natural size ; 6. Procarp with 



trichogyne C, hypogynous cell A, and carpogenic cell B. x 600; 5, a 

 later stage of the carpogenic branch of 6 showing the first divisions of the 

 carpogenic cell B. X 600 ; 10. Section of a spore-mass attached to carbo- 

 genic branch, x 500. 



7, 8, Ckrysymenia peudodichoto7na, 8. Showing tip of stipe and sack-like branches, 



twice natural size ; 7. Section of cystocarp. x 500, 



