191-i] Setchell: The Scinaia Assemblage 129 



matter how widely separated in locality and this has been done with 

 little question. It seems desirable, however, to examine these widely 

 distributed genera and species, particularly among the more highly 

 differentiated groups such as Florideae, to determine, if possible, how 

 far the seeming uniformity of structure extends and whether it is 

 really one species occurring so widely distributed or whether, in 

 reality, it may not be a group of more or less nearly related species, 

 each occupying its own limited domain. The cases thus far carefully 

 investigated have shown that the latter is the truth. One of the most 

 striking examples of this is Ceramium ruhrum. Another is, as shown 

 above, the alleged wide distribution of Scinaia furcellata. 



Scinaia furcellata has been reported from the ^lediterranean and 

 southwest coasts of Europe, from southern New England and Florida, 

 from the Cape of Good Hope, and from the Hawaiian Islands, from 

 New Zealand, Tasmania and Australia, from the west coasts of South 

 America, from the west coasts of North America, and from Japan. 

 As limited above, typical forms of Scinaia furcellata are found only 

 in Europe and Mediterranean north Africa and on the Atlantic coasts 

 of North America. Whatever else may be said of the various distinc- 

 tions drawn between the various species" in the present paper, it cer- 

 tainly seems demonstrated that none of them is true Scinaia furcellata 

 except as noted above. The distribution of this species, then, seems 

 natural from the point of view of occurring within limited tempera- 

 ture variation and with other temperate species of similar distribution. 

 Most of the regions credited with the possession of Scinaia furcellata 

 shows forms having a similar habit but of differing cortical or even 

 of differing cystocarpic structure. In the Australian region are two 

 species, externally resembling Scinaia furcellata but assigned, in the 

 present account, to different genera, viz., CloiopJiloea Scinaioides and 

 Pseudoscinaia australis. It is yet to be satisfactorily demonstrated 

 that any plant closely related to Scinaia furcellata occurs in the 

 southern hemisphere, the only species of the genus Scinaia absolutely 

 known to occur below the equator being Scinaia moniliformis and 

 Scinaia Salicornioides, regularly constricted species of decidedly 

 different utricular structure. At the Cape of Good Hope occurs a 

 cylindrical and unconstricted form previously referred to Scinaia 

 furcellata but which careful examination shows to be a Gloiophloea. 

 This has been given the name of Gloiophloea capensis in this account. 

 A study of the plants of the western coasts of the Americas shows no 

 true Scinaia furcellata. The South American plant is clearly a 



