188.3.) ^11 [Davenport. 



cise limits of each species be determined from the present incomplete 

 tables, we may ascertain from them, with a tolerable degree of certainty, 

 the range of certain species, and find material for some interesting observa- 

 tions. 



Thus we find the cosmopolitan Asplenium tricJiomanes and Pterin nqui- 

 liiia in thirty-five and thirty-nine, out of the forty-eight States and 

 Territories respectively, while their actual presence in a greater num- 

 ber may be safely assumed. Polypodium viilga7'e appears in thirty- 

 three, with the same, or an even greater probability of its occur- 

 ing in others in its favor, while its near congeners, P. californicum, 

 and P. faleatum, as well as P. scouleri are restricted to two or three States. 

 Of the remaining Polypodiums, all but incanum, which appears iu twelve 

 States are restricted to the single State of Florida, which furthermore 

 monopolizes all the species we have in six genera, the tropical character 

 of these baing 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 ferns presence) which may 

 now claim a monopoly of a genus is New Jersey, the very local Sehizcea 

 being restricted to a portion of its limits and again restricted to a single 

 species. 



Adiantum pedatum occurs in thirty-five States or Territories, while its 

 congener, A. capUlun-veneris, is restricted to thirteen, and the tropical A, 

 tenerum to a single State. 



The Osmundas are represented by one or more species in twenty-nine, 

 Onoclea in twenty eight States or Territories, and these probably occur in 

 more, although not reported west of the Rocky mountains. 0. sensihilis 

 extends as far west as Dakota and Montana, and in the last mentioned 

 Territory is said to have been discovered in a fossil state. 



Oystopteris 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. balbifera occurs 

 in twenty-five, covering a more unequal, but broader range south and 

 west, the limits of which terminate in Louisiana 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 Botrychia in forty-one States or Territories each, 

 while the di'ought-resisting Gymnogrammes, Notholsenas, Cheilanthes, 

 and Pellseas are almost wholly restricted to the arid regions west of the 

 Rocky mountains, a few scattering species only coming E.ist, North or 

 South. 



It is interesting to note the changes which have taken place in the num- 

 ber and distribution of our ferns since Red field published his valuable 

 paper on the "Geographical Distribution of the Ferns of North America," 

 in the Torrey Club Bulletin for January, 1875, and Watt, his admirable re- 

 view of Mrs. Lyell's Hand-Book in the Canadian Naturalist for 1870. Mr. 

 Redfield enumerated 133 species, Avhich have been increased up to the pres- 



PKOC. AJIER. PHILOS. SOC. SX. 113. 3y. PRINTED MARCH 30, 1883. 



