436 BULLETIN OF THE BUREAU OF FISHERIES. 
Order 1. Pheeosporeze Thuret. 
Phezozoosporine, De Toni, 1895, p. 293. 
Thallus multicellular (in a few forms one to few celled), varying greatly in size and 
form; asexual propagation by fragments of the thallus or special “brood buds”’ (pro- 
pagula) or by laterally biciliate zoospores, or by nonmotile aplanospores; sexual repro- 
duction by motile, laterally biciliate gametes, similar or differing in form and size, or 
by nonmotile eggs and laterally biciliate motile sperms; spores and gametes produced 
in organs (sporangia, gametangia) formed from ordinary vegetative cells or from special 
cells; sporangia and gametangia occurring on superficial portions of the thallus or arising 
from the transformation of surface cells. 
KEY TO FAMILIES. 
a. Sporangia and gametangia occupying the place of branches of the frond or formed by the 
transformation of segments or portions of these segments; longitudinal growth inter- 
calary. .. ‘ Sete: -I. ECTOCARPACE& (p. 436). 
aa. Sporangia Kaa pumiahaees formed by the Gaza sean Gaon or fe aiinee ve a superficial cell, 
less often arising from the evolution of single segments of a segmented portion of the 
frond; longitudinal growth by intercalary division equally distributed through the 
whole frond or persisting a longer time at the base; frond simple......, 2. ENCGELIACEA (p. 442). 
aaa. Sporangia and gametangia occupying the place of assimilating filaments or formed by 
the partial transformation of assimilating filaments..... 0.2.22... 2. eee c cece cee cece teen tees b. 
b. Longitudinal growth basal or lasting longest at the base........ 3. ELACHISTEACE& (p. 444). 
bb. Longitudinal growth terminal or subterminal................ 4. CHORDARIACE& (p. 445). 
@aaa. Sporangia and gametangia lateral on special segmented filaments arising from the frond......... c. 
eWangitudinal:srowth) sibtenm ina ee ee meitiaryrarelre ohm 5. STILOPHORACE4 (p. 447). 
cc. Longitudinal growth trichothallic; brushes of confervoid filaments at the ends of 
thetshort Dranchesucs).cewe see sae nee Me tele teineiisate rain eae Tes & 6. SPOROCHNACE# (p. 448). 
Family 1. ECTOCARPACE (Agardh) Hauck. 
Frond consisting of a creeping filament, usually with more or less conspicuous 
upright filaments arising from this, or of a one or two layered disk; usually monosiphon- 
ous, occasionally divided once or twice here and there in a longitudinal direction; more 
or less branched or subsimple; growth in length by intercalary division; sporangia and 
gametangia occupying the place of branches of the frond, or formed by the transfor- 
mation of articulations or segments of these articulations; organs of fructification 
consisting of “unilocular sporangia,’ formed by the growth of a cell without formation 
of cross walls, or of “plurilocular sporangia,’ formed by the growth and repeated divi- 
sion of one or more cells; these usually occurring on different individuals, sometimes 
apparently on the same individual; male and female gametes produced on the same or 
different individuals. 
About 130 species described, many of them doubtful, in all seas, but most abundant 
in the North Atlantic, mostly epiphytic. 
The method of reproduction is exceedingly various, even within a single genus. 
The family seems to show the beginning of differentiation into asexual and sexual cells. 
The products of the “unilocular sporangia’’ are asexual, either motile zoospores or 
nonmotile aplanospores. The products of the “plurilocular sporangia’”’ are asexual or 
sexual, being all alike, giving either zoospores or isogametes, or of two sizes, giving either 
zoospores of two sizes or heterogametes, or of three sizes, giving zoospores of two sizes 
