194 Chaetophoraceae 



Ten years later Fries confirmed the genus, describing the 

 species practically in the same order and adding two more. It is 

 not surprising that such a grouping was made, for in the general 

 appearance of the cells with the girdle-shaped chromatophore and 

 the mucous character of the filaments, these two groups have 

 more in common than many of the diverse elements at that time 

 comprised in the genus Conferva. Now these four unbranched 

 species were all placed in other genera before the establishment of 

 Kiitzing's Stigeoclonium and the removal to it of Myxonema lubri- 

 enm, our type. Hence whatever method of determining generic 

 types is followed, that of residues or that of priority of posi- 

 tion, since Myxonema lubricum was both the first species named 

 under the genus and also the last to remain in it, the conclusion 

 is inevitable that the genus Myxonema must stand upon this species. 

 Though it is always an unfortunate necessity that compels the 

 abandonment of a name long used for a large and comparatively 

 homogeneous group like Stigeoclonium Kiitz., reasons of sentiment 

 cannot weigh in cases of this kind. 



It should be noted that Rabenhorst ( '47) at first adopted the 

 genus Myxonema in practically the same composite sense as used 

 by Fries, and that later, instead of keeping the name for part of 

 the species, he abandoned it entirely for Kiitzing's genera Stigeo- 

 clonium and Ulothrix. 



Fries (Syst. Orb. Veg. 345. 1825) quotes as a synonym of his 

 new genus Myxonema, " Naematrix Fries, Stirp. Ferns.," but we 

 have been unable to find the latter name in the work quoted. 

 Perhaps it was a manuscript name which was finally rejected in the 

 publication of the Stirpium Agri Femsionensis Index, 1825-6. 



Other authors refer to Myxotrix Fries, Stirp. Ferns. 44, as a 

 synonym of Myxonema, but the only species is Myxotrix zonata 

 (presumably Ulothrix zonata); since no description or synonymy 

 is there given, this name needs no further consideration. 



Frequently one finds young or anomalous forms of Myxonema, 

 which it is almost impossible to identify with any described 

 species. On this account many specimens have been laid aside 

 during the preparation of this work. It is very desirable that such 

 young forms should receive continued attention, so that they may 

 ultimately be associated with their proper species. 



