213 
times desirable to question. These are the genus, the species, 
and the authority. If it was always understood that the mark 
cast doubt upon the word which it immediately followed, it could 
be used with an exactness which it does not now admit of. Is it 
not worth while for the committee to formulate a rule which will 
embody the above facts? F. H. Know ron. 
U.S. Nationat Museum, March 25, 1893. 
[It would seem that the interrogation mark placed as in the 
first and fourth of Mr. Sudworth’s models should indicate that the | 
author is in doubt whether he is or is not referring to the Ranun- 
culus aquatilis of Linnzus; placed as in the second model would 
indicate that doubt is thrown on Ranunculus aquatilis belonging 
in the genus Ranunculus, and would ordinarily only be employed 
in the first description of a plant. We see no particular applica- 
tion for the third method.—Ep. ] 
Further Notes on American Species of Polygonum. 
By Joun K. SMALL, 
(PLATE CLVI.) 
Since the publication of my Preliminary List of American 
Species of Polygonum in the BuLLETIN of December, 1892, I have 
had an opportunity to examine and study, among other collections, 
those of the Geological and Natural History Survey of Canada 
and the California Academy of Sciences. The former is rich in 
specimens from the territory north of the United States, and the 
latter is remarkably well stocked with rare and interesting Western 
material, as well as some of the very scarce species from the Andes 
of South America. 
The following notes and descriptions of new forms are the re- 
sult of some observations on the different. species recorded below. 
I also take occasion in this place to ask collectors, in whatever 
part of the country they may be, to gather all the forms of the 
genus under consideration that they may meet with during the 
coming season. 
POLyconum SAWATCHENSE, n. sp. Annual; more or less scurfy or 
papillose throughout, of a dull green color; stem erect, striate, 
obscurely four-angled and four-winged below the ocrez, 
