144 Ulothricaceae 



their work might have had a more trustworthy character if it had 

 been dealt with more critically during its progress. Indeed, we 

 have been keenly sensible of the lack of criticism upon our own 

 work. It is, perhaps, too easy to find fault with the work of others, 

 and not so easy as one could wish to make great improvement 

 upon their work. The meagerness of the older and of some recent 

 descriptions where the only important characters are size and shape 

 of cells, often makes it a matter of great difficulty to determine 

 species. We have endeavored to emphasize cytological and espe- 

 cially chromatophore characters as much as possible, but often one 

 cannot find important distinctions of that nature, and is forced to 

 rely largely on cell-measurements to separate species which, after 

 careful observation, he is convinced are distinct. It has been par- 

 ticularly disappointing, in the attempt to make synopses of species, 

 to find that even now the use of cell-measurement is one of the 

 most convenient means of separation and has been resorted to in 

 a much greater degree than had been expected. 



It is a pleasure to make grateful acknowledgment of the en- 

 couragement and counsel, as well as sympathetic companionship 

 in laboratory and field, of Professor L. M. Underwood and others 

 of the Botanical Department of Columbia University, and to express 

 our thanks to those who have furnished specimens for study, and 

 given guidance in collection, notably Mr. F. S. Collins, Mr. Isaac 

 Holden, Professor G. E. Stone, Dr. David Griffiths, and Dr. M. A. 

 Howe. 



Order CHAETOPHORALES * 

 Family ULOTHRICACEAE 



The thallus consists normally of a simple, unbranched, fila- 

 ment of uninucleate cells, which are all (the basal cell only, when 



*This new name for the order which has been known as Confervales is proposed 

 by Wille (Nyt Mag. for Naturvid. 3g : 1-22. 1901), because the latter name is ren- 

 dered unsuitable in consequence of the removal by recent authors of the genus Conferva 

 from the Ulothricaceae. The name of the order Confervales Borzi, including the new 

 family Confervaceae, the Ophiocytiaceae, etc., is confusing in view of the older order 

 Confervales, and ought, moreover, to be changed because the genus Conferva Lagerh. 

 should be known as Tribonema Derb. & Sol. 



Professor Wille appears to take a backward step in the paper cited, in that the 

 Ulothricaceae are there placed under the Ulvaceae. The two families are closely 

 related, and possibly almost overlap, but it seems more convenient to retain both. 



