590 University of California Publications in Botany [Vol. 8 



Kuetzing-, Tab. Phyc, vol. 6, 1856, p. 19, pi. 52, II ; Setchell, Alg. 

 Prib. Is., 1899, p. 591 ; Setchell and Gardner, Alg. N.W. Amer., 1903, 

 p. 248. Dictyosiphon Chordaria f. gelatinosa Setchell and Gardner, 

 Alg, N.W. Amer., 1903, p. 248 (not Stroemfelt). Scytosiplion hip- 

 piiroides Lyngbye, Hydr. Dan., 1819, p. 63, pi. 14 B. 



D. hippuroides resembles D. foenicid.aceiis very closely, and is often 

 confused with it. It is a coarser plant generally, is less profusely 

 branched, each order of branches approximating the same size, and is 

 less tapering. Collins (Rhodora, 1900, p. 164) states that this species 

 frequently reaches a meter in length on the Atlantic coast. The mate- 

 rial which we have referred to this species is scanty and of small size. 

 Some of our plants may possibly be referred to the var. fragilis 

 (Harv.) Kjellman. 



Order 6. LAMINARIALES oltmanns 



Fronds of large size, solid or hollow, simple or branched, cylindrical 

 to flattened, usually with three distinct regions, viz., (1) a holdfast 

 varying from discoid to clusters of simple or branched hapteres, (2) 

 a stipe cylindrical or more or less flattened and simple to dicho- 

 tomously or irregularly branched, and (3) a flattened blade or blades, 

 of usually three sets of tissues, inner of colorless, elongated, usually 

 intertwined, hyphal cells, some with enlarged ends ("trumpet hy- 

 phae"), intermediate of somewhat vertically elongated or nearly 

 isodiametric cells with scattered chloroplasts (phaeoplasts) passing 

 over into an outer layer of small cells usually deeply colored ; mucilage 

 glands, or canals, present in some species; zoosporangia on macroscopic 

 sporophylls, borne in extended sori, accompanied by closely packed 

 unicellular paraphyses having, usually, terminal hyaline appendages; 

 growth in length from a meristematic tissue intercalated between blade 

 and stipe, or, in Chordaceae, just above the holdfast ; gametophyte 

 microscopic, usually very much reduced, confervoid, bearing uni- 

 locular gametangia ; sperms motile, biciliate ; eggs non motile, fertilized 

 and germinating in position. 



Oltmanns, Morph, und Biol, der Algen (ed. 2), vol. 2, 1922, p. 121. 



The discoveries by Sauvageau (1915) and by Kylin (1916, 1918) 

 of the gametophytes of several members of this group inaugurated a 

 change in the whole attitude toward the classification of the Brown 

 Algae and led to interpretations of certain peculiarities of the occur- 

 rence of the reproductive bodies in certain groups. Following these 



