502 University of California Publications in Botany [Vol. 8 



as described by Kjellman (loc. <■!!.). The specimens were all sterile. 

 We have seen no data as to the reproductive characters of the species 

 since. A single collection of sterile material taken by one of us 

 (Setchell) at St. Michael, Alaska, in July, 1899, was referred by us 

 (loc. ril.) to tli is species. A reexamination of the material and com- 

 parison with material of the type collection, demonstrate that the, 

 Alaskan plants are different, but without assisting in definitely 

 placing them. 



family 5. ELACHISTEACEAE kjellman 



Thallus pulvinate or penicillate, more or less lubricous, composed 

 of loosely to compactly intertwined, more or less monosiphonous fila- 

 ments at times agglutinating or anastomosing and forming a pseudo- 

 parenchymatous base, often penetrating the host below and always 

 giving rise above to numerous free assimilating filaments, either 

 zoosporangia or gametangia or both and at times colorless hairs ; game- 

 tangia uniseriate or interruptedly pauciseriate, occasionally lateral, 

 single or grouped; "paraphyses" present or absent. 



Kjellman, Handbok Skand, Hafsalgfl., I, 1890, p. 41 ; Folsie, Contr. 

 knowl. mar. alg. Norway, I, 1890, p. 92. Elachisteae Reinke, Algenfl. 

 westl. Ostsee 1889a, p. 49. 



The family of the Elachisteaceae, as separated and indicated by 

 recent writers, includes a number of pulvinate species, all small, but 

 some even minute, largely epiphytes, or possibly growing at times on 

 rocks. They are to be distinguished by their basal portions. In 

 Elachistea, the basal portion is solid due to the agglomeration, or 

 anastomosing of the filaments in this portion of the thallus. In 

 Halothrix, Giraudia, Symphoricoccus, Leptonema, etc., the basal por- 

 tions of the filaments are not united to any considerable extent or at 

 all, but are intertwined and woven together to form a spongy mass. 

 We are inclined to refer to this family C ' ylindrocarpus microscopicus 

 Crouan (cf. Kuckuck, 1899, pp. 49-55, figs. 1-5) as being a link 

 between the Ectocarpaceae and the Elachisteaceae but, because of its 

 pulvinate habit and densely interwoven filaments, approaching the 

 Elachisteaceae more nearly than typical Ectocarpaceae. Several 

 species of Ectocarpus and especially E. hemispheric!** Saund. seem 

 to foreshadow the Elachisteaceae, but are not sufficiently compacted 

 or agglutinated at the base to properly be included in this family. 

 The method of origin of the tufts of the members of this family does 

 not seem to have been traced, but prostrate filaments, either free or 



