BENEDICT: REVISION OF THE GENUS VITTARIA 393 
features of scale differences and to have made several species 
from what should properly be included in only one. Mettenius* 
and Luerssenf described and figured accurately some of the im- 
portant differential characters of leaf outline as seen in section, 
but neither writer covered many species. More recently Jeffreyt 
and Mrs. Britton and Miss Taylor§ have described and figured 
carefully the morphology of one or two species each. The present 
paper represents an attempt to describe and figure as thoroughly 
as necessary the differential characters of the seven species included 
in the subgenus Radiovittaria, as I have recently described it. 
As has been noted, these seven species are all American. 
The work of which this paper, as also the earlier paper on the 
genera of the tribe Vittarieae, is a partial report, has been carried 
on intermittently during the last six years at the New York 
Botanical Garden. The present article was brought nearly to 
completion during a month’s residence as research scholar during 
parts of November and December, 1911, also at the N. Y. Botan- 
ical Garden, and I am glad to acknowledge my indebtedness to 
Dr. N. L. Britton for the opportunities of study thus afforded. 
In general the material studied has been sufficiently cited in my 
earlier paper on the genera of the tribe, but important additional 
material has been received from the collections of Mr. W. R. 
Maxon in Panama, and I have also been greatly aided by Mr.. 
Maxon’s descriptions of the field conditions under which his. 
material grew. 
The present paper deals with less than one fifth of the total 
species of Vittaria, but in order that the problems of the characters 
and nomenclature may be clear at the start, a description of the 
genus and its synonymy are included and also a discussion of its 
division into subgenera. 
VITTARIA J. E. Smith, Mem. Acad. Turin §: 413. pl. 9. 1793 
(Type species Pieris lineata L.) 
Haplopteris Presl, Tent. Pterid. 141. 1836. 
* Fil. Hort. Bot. bibs 25-27. pl. 27, f. 21, 22. 1856. 
} Schenk & Luerssen, Mittheil. ae I: 57. pl. 11-19. 1871. 
} Phil. Trans. Roy. Soc. London 19§ B: 119-146. pls. 1-6. 11 Je 1902. 
§ Mem. Torrey Club 8: 185-211. pl. 28. 1902. 
