408 University of California Publications in Botany [Vol. 8 



Lyng'bye established the genus Ecto-carpus on six species, the last 

 two mentioned of which are not even members of the Melanophyceae. 

 The other four are wholly, or in part, members of the genus as limited 

 by Bory, in which sense it has more recently been taken by many 

 writers. The only confusion has been with Pylaiella and there may be 

 a question as to the wisdom of segregating that. The first species listed 

 by Lyngbye is Ectocarpus littoralis but, as we have already indicated, 

 Lyngbye's conception of this species included a true Ectocarpus as 

 well as what we now separate as Pylaiella. littoralis. Otto Kuntze 

 (1891, p. 888 and 1898, p. 401) has attempted to revive the Rafines- 

 quian name Colophermum (1814) for Ectocarpus, but the latter name 

 has been included among the "nomina conservanda" by the Brussels 

 International Botanical Congress (cf. Briquet, 1912, p. 75). 



We have already set forth the distinctive features of the genus 

 Pylaiella, separating it from the other genera of the family. Ecto- 

 carpus differs from Strehlonema in that the creeping basal filaments 

 either do not penetrate the host-plant at all, or do so only very slightly, 

 or, at least, the greater portion of the frond is free. It is frequently 

 a delicate matter to decide whether a certain species may better be 

 referred to Ectocarpus or to StreMonema, yet it seems best to keep 

 them separate. 



In habit and stature, the species of Ectocarpus differ considerabh^, 

 some being very low and dwarfed, while others are tall; some are 

 tufted, some are feathery, while some have their filaments entangled 

 into ropy masses. The zoosporangia are either more rare or less fre- 

 quently found than the gametangia and are unknown in many species. 

 The gametangia differ much in the various species, in shape, size and 

 position. In some species they are dimorphic or even polymorphic 

 (Sauvageau, 1896, pp. 27 and 32, 1896a, 1896&, etc.). In some species 

 there are "megasporangia" (as Sauvageau calls them) Avith large 

 divisions (loculi), " meiosporangia " (Sauvageau) with medium sized 

 divisions (loculi), and antheridia with very small divisions (loculi). 

 It is supposed that the motile sperms are produced by the antheridia 

 and one or the other of the mega- or meio- gametangia produce the 

 egg cells (cf. Sauvageau, 1896c). Much more experience is needed 

 before we may be able to decide the question of the function of these 

 different gametangial structures. They are usually lateral and either 

 sessile or pedicellate. More rarely are they terminal and, at times, 

 even intercalary^ (e-g-, E. siliculosus f. varians Kuckuck, 1892, p. 256, 

 pi. 13). 



