NO. 1 TAYLOR: PACIFIC MARINE ALGAE 137 



the plants here referred to G. veprecula and G. stupocaulon. This is con- 

 jectural, since not experimentally proved. In a few species the repeated 

 incidence of two "species," and only two, at the same place and time makes 

 it reasonable that they may be the alternate phases of the same specific 

 entity, but in other cases it is probable that the sexual and the asexual 

 phases are prevalent at different seasons. Consequently, it is only in a few 

 instances that this relationship is fairly clear in the dimorphic types. 

 Furthermore, there are instances where a group of fairly distinct "species" 

 (if one considers only one phase, such as the asexual) seem to correspond 

 to an assemblage of very closely similar forms in the other phase, which 

 can only indefinitely be segregated into "species." It is not yet clear if 

 we should use simple priority in establishing the correct name when we 

 do demonstrate the true relationships, or if we should designate the 

 earliest-used name for the asexual or the sexual phase, disregarding the 

 other form. 



As a result of this confusion it has become customary not to try to 

 associate the sexual and the asexual plants taxonomically, but to describe 

 them independently. It is not possible to associate them from the casual 

 collections of exploratory parties, but it will in time probably be possible 

 to do so on the basis of seasonal studies in the field. While an earnest 

 attempt was made to pair up the Hancock Expedition "species," little was 

 accomplished. Rarely did more than one occur in a given collection. The 

 taxonomic situation established by this practice is unfortunate, but not 

 susceptible of immediate improvement; certainly in many cases there are 

 no morphological clues to the relationship. 



Certain Pacific material of Galaxaura is being monographed by Miss 

 Ruth Chen-Ying Chou; the key and the descriptions here included are 

 based on her manuscript, and in turn on Hancock Expedition or other 

 Pacific material, and she has made the determinations, for which help the 

 writer is very grateful. The determinations have been made with every 

 effort to preserve the Kjellman attitude toward the genus ; certain distinc- 

 tions are by no means clear, as in the group Brachycladia, but this seemed 

 the best method of approach for the time being, and the most likely to 

 keep all forms separate which should conceivably be distinguished. 



KEY TO SPECIES 



1 . Plants asexual ; outer assimilatory tissue filamentous, composed of 

 stalk and terminal cells 2 



1. Plants sexual; peripheral tissue parenchymatous, composed of a 

 continuous epidermis and a hypodermis 7 



2. Plants with branches terete throughout, at least in part villous 3 



