THE GREEN ALGAE OF NORTH AMERICA 85 



Farlow of Harvard University the writer owes his first encour- 

 agement in the study of algae ; for this, for assistance and 

 advice through many years, and for the opportunity to consult 

 his unrivalled library and collections, the most hearty acknowl- 

 edgement is offered. With Prof. W. A. Setchell of the Uni- 

 versity of California the writer has been associated for many 

 'years in collecting and studying, and much of value in the 

 present work is due to his contributions and suggestions. That 

 so good a representation can be given of the green algae, marine 

 and fresh water, of the Pacific coast States, is chiefly due to Dr. 

 N. L. Gardner of Los Angeles, California, an acute observer 

 and indefatigable collector. To many Kuropean botanists 

 thanks are due for information as to types and for materials 

 for comparison ; most of all to Dr. Edouard Bornet of Paris, the 

 value of whose advice and assistance is equalled only by the 

 unfailing promptness and courtesy with which they were given. 

 To Prof. J. S. Kingsley and Prof. F. D. Lambert of Tufts 

 College, the writer is indebted for opportunities for collecting 

 and study during the seasons he has been at the Laboratory at 

 Harpswell, Maine, and for many facilities given and kindnesses 

 shown ; the plates which it is hoped will add materially to the 

 value of the paper are also their work. 



No one can know as well as the writer how incomplete the 

 work is, and how likely it is that errors will be detected ; but 

 no pains have been spared to make it as complete and accurate 

 as possible. There can be no question that a work on the sub- 

 ject has been needed ; if this will stimulate study and increase 

 knowledge, so that a better work can soon take its place, it will 

 have justified its existence. 



Before algae are studied they must be collected, and a few 

 hints in this regard may be of use. Only the green algae will 

 be taken into account in this respect, but as the different types 

 of green algae require different treatment, practically every 

 contingency as to other types of algae will be provided for. In 

 temperate regions the marine green algae are largely littoral 

 plants, that is, inhabiting the zone between high and low water 

 marks ; in quiet bays and pools they may form dense floating 



