59 
m - I 
certainty the range of certain species, and find material for some in- 
teresting observations. 
Thus, we find the cosmopolitan Aspleninm trichomanes and Pteris 
aqiiilina in thirty-five and thirty-nine out of the forty-eight States 
and Territories respectively, while their actual presence in a greater 
number may be safely assumed. Polypodiumvidgare z.^^^^d.x'^ in thir- 
ty-three, with the same, or an even greater probability of its occur- 
falcatuin 
Califi 
States. Of the remaining Polypodiums, all but incanum^ which ap- 
pears in twelve States, are restricted to the single State of Florida, 
which furthermore monopoHzes all the species we have in six genera, 
the tropical character of these being at once indicated by this fact. 
The only other State (since the discovery of Scolopendrium in 
Tennessee has divided with New York the honor of that fern's pres- 
ence) which may now claim a monopoly of a genus is New Jersey, 
the ^very local Schizcea being restricted to a portion of its limits, and 
again restricted to a single species. 
Adiantumpedaium occurs in thirty-five States or Territories, while 
Its congener, A, Capillus- Veneris^ \s xtsiiicicd to thirteen, and the 
tropical A, tenerum to a. single State. 
The Osmundas are represented by one or more species in twenty- 
nine, Onodea in twenty-eight States or Territories, and these prob- 
ably occur in more, although not reported west of the Rocky \ioun- 
tains. O. sensibilis extends as far west as Dakota and Montana, and, 
in the last-mentioned Territory, is said to have been discovered in a 
fossil state. 
^ Cystopteris fragilis extends, from Maine to California, through 
thirty-three States and Territories, apparently avoiding the South 
Atlantic and Gulf States, with the exception of North Carolina, while 
C.bulbifera occurs in twenty-five, covering a more unequal, but 
broader range south and west, the limits of which terminate in Lou- 
isiana and Dakota. C, montana, so recently discovered in Colorado 
■by Brandegee, is reported elsewhere in the United States only from 
Alaska. The Aspidia are represented in forty-four, the Asplenia and 
Bortrychia in forty-one States orTerritories each, while the drought- 
resisting Gymnogrammes, Nothohnenas, Cheilanthes and Pellasas are 
almost wholly restricted to the arid regions west of the Rocky Moun- 
tams, a few scattering species only coming east, north, or south. 
It is interesting to note the changes which have taken place in 
the number and distribution of our ferns since Redfield published 
his valuable paper on the '' Geograhhical Distribution of the Ferns 
of North America," in the Torrey Club Bulletin for January, 
3875, and Mr. Watt his admirable review of Mrs. Lyell's Hand-Book 
in the Canadian Nattiralist for 1870. Mr. Redfield enumerated 125 
species, which have been increased up to the present time to 153 or 
156, according as we may consider the claims of certain ferns to 
specific rank, or their right to a place in our fern-flora, while the 
range of the older species has been more or less extended. 
. Taking the number in the list accompanying this paper for a base, 
^^^•> ^55> we have since 1875 an increase of 30 species. 
