THE OEDOGONIACEE 

INTRODUCTION. 
Perhaps the most sharply circumscribed and clearly delimited 
group among the green alge is the family Oedogoniaceee. The 
members of its three genera—Bulbochaete, Oedocladium, and 
Oedogonium—are not only easily separable from other fila- 
mentous algz but also readily distinguishable from each other. 
The rather rigid vegetative cells, the prominent reproductive 
organs, the large zoospores each with a crown of cilia at the 
anterior end, the reticulate chloroplasts, and the attached 
habit are characteristics of the family. 
The filaments of Bulbochaete are branched and composed of 
cells each bearing at its enlarged upper extremity a laterally 
placed hair or seta. The sete are bulbous at the base, hollow, 
and frequently greatly attentuated, sometimes reaching a 
millimeter in length. Oedocladium is also branched but is 
devoid of hairs. Species of Oedogonium are unbranched and 
in common with Bulbochaete possess holdfast cells that provide 
attachment for the plants. Oedocladium hazenii* and species of 
both Oedogonium and Bulbochaete are aquatic. The remain- 
ing three species of Oedocladium are terrestrial. 
The family Oedogoniaceze was established by De Bary in 
1854; the genus Bulbochaete by C. A. Agardh in 1817; Oedo- 
cladium by Stahl in 1891; and Oedogonium by Link in 1820. 
The most noteworthy contributors to the taxonomy of the 
group, other than those above, have been Pringsheim, Wittrock, 
Nordstedt, and Hirn. Since 1900 a number of algologists 
have added to our knowledge of the family by descriptions of 
new species, further notes on life histories, and data on geo- 
graphic distribution. A list of such workers includes Hirn and 
Hallas from Finland; William West, G. S. West, Fritsch, 
Carter, and Hodgetts from England; Borge from Sweden; 
Wille and Strom from Norway; Pascher and Heering from 
Germany; Skuja from Latvia; Collins, Transeau, Lewis, and 
Tiffany from the United States. There have been many other 
*In the Index the name of each new species, variety, or form is preceded by 
an asterisk. 
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