IV. ECTOCARPACE^.— EcTocARPUs. 141 



dispose of it otherwise, I must consider it for the present as a doubtful species ; — 

 muddy in more respects than one. Its colour in the dry state is brownish. 



Plate XII. A. Fig. 1, Part of a filament of Ectocarpus lutosus, magnified ; 

 fig. 2, minute portion, with pi'opagida, highly magnified. 



*** Propagida oval, ellipsoidal or conical, sessile or pedicellate, scattered. 

 6. Ectocarpus tomentosus ; Lyngb. ; filaments very slender, flexuous, irregularly 

 branched, interwoven into a dense, sponge-like, branching tuft ; propagula ellip- 

 soidal, obtuse, pedicellate. Harv. Phyc. Brit. t. 182. /. Ag. Sp. Alg. 1, p. 23. 



Hab. On various substances between tide-marks. Prince Edward's Island, Dr. 

 Jeans. Boston Bay, Mrs. Asa Gray. (v. v.) 



The sponge-like tufts of this plant, composed of innumerable densely matted, 

 flexuous, branching filaments, are from two to six inches long or more, and divided 

 into several branches, which are either simple or furnished with lesser divisions. 

 The filaments are very slender, and most irregularly branched, the branches 

 flexuous, secund or alternate, and of various lengths. Articulations twice or thrice 

 as long as broad, pellucid. Propagida pedicellate, linear-oblong or ellipsoidal, very 

 obtuse. Colour varying from yellowish olive to dark brown. 



The densely interwoven, rope-like, branching tufts at once mark this species from 

 most others. 



7. Ectocarpus fasciculatus, Harv. ; tufts olivaceous, dense ; main filaments not 

 much divided ; the branches distant, set throughout with alternate or secund 

 fascicles of subulate ramuli, the ramuli secund in each fascicle ; propagula sessile, 

 secund, several together, ovato-acuminate or subulate. Harv. Phyc. Brit. t. 273. 

 J. Ag. Sp. Alg. \,p. 22. 



Hab. On the larger Algce between tidemarks, generally on the Laminaria?. 

 Rhode Island, Mr. Olney, Prof. Bailey, and Mr. G. Hunt. Also in Herh. J. Hooper. 



(V. V.) 



Tufts dense, 3—6 inches long, entangled and rope-like at the base, free and 

 feathery above ; the ultimate ramuli densely aggregated ; appearing under a 

 pocket-lens to be fasciculate, but not strictly so, being only placed in secund series 

 close together. Articidations once-and-half to twice as long as broad. Colour vary- 

 ing from olive green to duU brown or rusty. Substance soft, adhering to paper. 



8. Ectocarpus gramdosus, Ag. ; tufts olivaceous, lax, feathery ; filaments capil- 

 lary, elongate, much branched : branches free, opposite, spreading ; ramuli opposite 



