282 THE JOURNAL OF BOTANY 



Gen. Htpnum. 

 Dendro-Hypmim, 



62. Dendro-Hypnum fasciculaium S\v. 



Platy-Hypnum. 



66. HuglossojjJiyUum radiculosiim C. M. Synops. 



Sect. Vesicularia. 



68. Hypnum suhdenticulatum C. M. Synops. 



69. IE* I city -Hypnum splendidulum Hornsch. Fl. Brasil. 



It will, I think, be generally felt that the substitution of Bliizo- 

 Hypnum for Stereo-Hypnum in no way helps matters. 



I have not myself adopted any of these substitutes for Micro- 

 thamnium, but I have published one or two species under Mitten's 

 name, and have thereby incurred some friendly criticism from fellow- 

 bryologists. There have appeared to me several i-easons for following 

 this course. In the first place, assuming that Mitten's name came 

 under those which by the International Law^s become disqualified, 

 there is still the list of " Nomina con servanda "to be drawn up for 

 mosses, and it would be quite reasonable to suppose that when the 

 time comes for this to be done, Microiliamnium might find a place 

 on that list. It has been established for more than fifty years ; it is 

 a rather large genus, containing at least a hundred species, and the 

 consequent new combinations needed are therefoi'e not inconsiderable. 



In the second place, of the three names proposed as substitutes, 

 all have at least some faint suspicion attached to them as to their 

 absolute compliance with the laws of valid publication, and it is 

 doubtful whether unanimity would be reached b}' this road. And, 

 thirdl}^, it is held by some competent botanists that an existing 

 generic name should not be rendered invalid in one of the great 

 divisions of the Vegetable Kingdom b}^ reason of its previous employ- 

 ment in another. As the International Laws stand, this position can 

 at present, perhaps, hardly be taken, but it might fairly be argued 

 that it is at least open to consideration under the special arrangements 

 "reserved for the Congress of 1910" (see Intern, llules, Art. 9, 

 footnote 1). 



I have briefly stated the above arguments, because it appears to 

 me that they apply with some force not only to the case under con- 

 sideration, but to any proposed alteration in bryological nomenclature 

 involving rather considerable changes at the present time. But the 

 main object of this note, and my chief ground for maintaining the 

 validity of Microfhamnium Mitt., rests upon a quite different con- 

 sideration which has recently come to my notice. 



All the authors cited above appear to have accepted Hennings's 

 dictum that JSIicrotliamnium Mitten is antedated by Microthamnium 

 Naegeli, genus Alyarum. But, as a matter of fact, this is incorrect. 

 Naegeli's name is published in Kuetzing, Sp. Algarum, p. 352 (1849), 

 and appears thus : — 



MiCROTHAMNiox, Nciegell in litt. 

 M. Kuetzlngianum Naegeli, No. 221. 



There has, so far as I know, never been any variation in the 

 spelling ; it has alwav's been cited as 3Iicrot1i amnion Naegeli. 



It is quite evident that the case falls under Art. o7 of the Intern. 



