THE GREEN ALGAE OF NORTH AMERICA 81 



Under each species will be found a concise description, with a 

 record of the localities in which it has been found ; if in the 

 United States, the State is given, but seldom any more exact 

 location. Reference is given to the original publication of the 

 binomial, also to some good plate or figure ; where there has 

 been distributed in some set of exsiccatae a specimen that can 

 be identified with the species in question, reference is made to 

 this ; by preference use is made of the Phycotheca Boreali- 

 Americana of Collins, Holden & Setchell, as being at once the 

 fullest for American algae, and the most accessible for Ameri- 

 can students. References are also given to three standard 

 works : Harvey, 1852, Farlow, 1881, and Wolle, 1887. Where 

 the basis of treatment of any family or genus has been the 

 monograph of any author, reference is made to such monograph 

 under each species. In special cases other references have 

 seemed desirable, and have been made. 



In the plates there will be found at least one figure for each 

 genus ; in most cases these are taken from standard works, 

 often from the original description of the species represented. 

 Where a choice had to be made of the species to be represented, 

 in some cases a type was selected other than the one most famil- 

 iar to American students in the usual text books. 



It has not seemed necessary to furnish any glossary of botani- 

 cal terms used, but such terms as are special to the forms here 

 described, and which would not be found in ordinary botanical 

 works, have been included in the index, with a reference to the 

 page in which they are used and explained. 



In the present imperfect state of our knowledge of the green 

 algae, it would be unsafe to make deductions as to distribution 

 from the records of localities here given, that is, as to their ab- 

 sence from regions not noted. In fresh water algae especially 

 the greater part of our territory is "terra incognita." Begin- 

 ning at the north, we have Greenland-, with a limited flora of 

 fresh water algae, but probably as completely known, thanks to 

 the Danish botanists, as that of any other region of the same 

 size within our scope. New York and New England have been 

 considerably explored, and there are some few records from 

 West India Islands. The fresh water algae of California : nd 



