INTRODUCTION 9 
case of Neurocarpus vs. Dictyopteris and Halyseris,* we have not 
hesitated to give preference to the oldest name, beginning with 
Linnaeus’ “Species Plantarum," in accordance with the provisions 
of the "American Code," without regard to the list of nomina 
conservanda of the Brussels Congress. On the other hand, there 
are many cases, as, for example, most of the new generic names 
imposed upon algae by Rafinesque, in which, in default of authentic 
specimens, the correct application of the name must remain 
involved in doubt, or 11 which, perhaps, the application may seem 
clear to one phycologist and obscure to another equally competent 
tojudge. In all such cases we have never intentionally sacrificed 
certainty to uncertainty. Іп several such cases, in some others 
that have appeared unusually complicated апа of doubtful solu- 
tion, and in certain others in which a drastic application of the 
American Code has seemed to lead to confusing and unhappy 
results, we have felt relieved to find at least a temporary solution 
of our difficulties in the list of nomina conservanda" prepared by 
the Brussels Congress. We confess also to a personal prejudice 
against the revival of ancient adjectival generic names such as 
Amphibia, Hyalina, Bifida, etc., of Stackhouse and the Vertebrata 
of S. F. Gray. The fact that a few not altogether dissimilar 
names have secured a foothold in the language of botany and have 
become classic does not seem an adequate excuse for the admission 
of a small host of others which, by common consent, have been 
almost universally ignored. 
ACKNOWLEDGMENTS 
If the present attempt to describe and enumerate the marine 
algae of Peru possesses any degree of accuracy, it is due in large 
measure to the generous cooperation of the owners or custodians 
of the original South American materials on which numerous 
species described by C. Agardh, Bory, Montagne, J. Agardh, 
Kützing, and others were based. Through the helpful courtesies 
of the fortunate possessors of these original specimens we have 
been able to examine the types or at least photographs of the 
types of nearly all of the species, South American and otherwise, 
* In this particular case, the Brussels Congress named Dictyopteris as the nomen 
conservandum, even though the preponderance of “usage” during the past fifty years 
eems to have favored Halyseris. 
