PLAN OF THE CATALOGUE. 15 



in classification, arrangement, and nomenclature, for the marine 

 Algae. ^ In every case where descriptions of genera or species 

 found at Mount Desert do not appear for any reason in these 

 works, the authors have tried to give them in the Catalogue, 

 hoping thereby to render unnecessary any reference to works or 

 articles not readily accessible. It is believed that our plan has 

 been adopted throughout with some slight exceptions, most of 

 which need no explanation. 



V. It has, however, been thought well to adopt throughout 

 the Catalogue the parenthetical citation of the original au- 

 thor of the specific or varietal name, a method already long 

 adopted by cryptogamic botanists. Thus Coptis trifolia, the 

 common Goldthread, was described in 1753 by Linnaeus under 

 the name of Hellehorus trifollus. In 1798, Salisbury consid- 

 ered that the plant showed well marked generic differences, and 

 assigned it to a new genus, Cojitis. Our plant therefore bears 

 the binomial, Cojitis trifolia (L.), Salisb. It must be borne in 

 mind, however, that the author cited in parentheses is cited 

 only for the specific or the varietal name in the binominal, as 

 the case may be, and is connected with that alone, and not with 

 the binominal itself. To the binominal, the name of the 

 author not cited in parentheses alone applies. If these dis- C/ 

 tinctions be remembered, many of the objections that have 



been so forcibly urged against this method of citation seem to 

 lose their weight. 



VI. The term <'form" — forma — has been used for the 

 sake of convenience to indicate slight physiological or struc- 

 tural variations seeming of hardly enough importance to mark 

 a good variety, much less a species, and yet worthy of some 

 notice, perhaps of future study. Allowance once rightly made 

 for variation in nature, it becomes a very complex and difficult 

 matter to decide what is a species, what a variety, what a 

 form, what a variation. Without discussion of the subject, it 

 may be said that it has seemed best to recognize as forms sub- 

 stantially the same variations that are indicated by Dr. N. L. 



1 Siee introductory note to the list of Algas for a fuller statement of the 

 plan adopted. 



