
          of ferns that I have not yet been able to study.

 I believe the Aspidium noveboracense to be a distinct
 species from the A. thelypteris [Aspidium thelypteris] - this distinguished by the
 lower pinnae running far down the stipe, gradually
 diminishing in size and being wider apart. It appears 
 later in the Spring, and instead of growing in masses in wet
 spots on the border of woods and sphagnous places, it prefers
 a damp open wood. The frond is of a deeper green, and in
 fruit the margin is not so sevolute.

 I am impatient to hear or rather read your latest
 opinions upon our ferns. I am very curious to know if you
 acknowledge both Aspidium cristatum & Lancastriense. I
 have often examined the swamp at West Cambridge which
 Bigelow assigns as the habitat of the latter, and found only
 the fern so common in wet places which does not agree
 with specimens of the Cristatum from England, but I suppose it is
 so named by our authors. Bigelow thought that the fern
 found in the swamp is not the Lancastriense.

 I cannot make out any different plants to correspond to
 Aspidium dilatatum, Aspidium intermedium, Aspidium spinulosum
 or to Aspidium filix-femina & Asplenioides [Aspidium asplenioides] & Angustum [Aspidium angustum].

 I have never seen Aspidium schweinitizii, Woodsia ilvensis
        