4-6 NEW YORK STATE MUSEUM 



Peck collections will be used in this paper to illustrate the proposed 

 arrangement. 



The spores of the different species of Inocybe are of two main types. 

 In one type the epispore is smooth and rounded. In the other type 

 it is ornamented by spines, nodules, or a more or less tuberculate 

 roughness, which is usually associated with somewhat angular shape. 

 This angularity may be sharply marked or obscure and is somewhat 

 masked by the roughness due to the tubercles. In a very few cases 

 ( for example I. d e c i p i e n s Bres. and I. maritimoides 

 Pk.), the spores are merely angular or with only very slight or few 

 elevations on the surface. The nodules (tubercles meaning practi- 

 cally the same) may be crowded, or, as is frequently the case, scat- 

 tered on the surface of the spore. Furthermore, they may be coarse 

 and prominent under the ordinary high-power maf^rnifications (that 

 is, without the use of the oil-immersion lenses), or may be indistinct 

 and then best seen by causing the spores to roll over during observa- 

 tion under the microscope. 



The cystidia are either present or lacking and the species are thus 

 easily grouped into two parts. They may be very numerous or 

 rather thinly scattered over the hymenium and in a few species so 

 few that a very small portion or section of the gills may fail to 

 show an}'. They may be present all over the surfaces of the gills 

 or mostly on the edge of the gills or near the edge. The latter state- 

 ment contradicts the statement of Massee (Annals of Botany, 18:462, 

 1904) in which he claims that " true cystidia are only met with on 

 the surface of the gills." In order to discriminate on the subject, it 

 must be noted that all species of Inocybe develop, on the edges of 

 the gills sac-shaped or rounded-clavate, more rarely subacute or capi- 

 tate cells, which I have designated " sterile cells " ( Agaricaceae of 

 Michigan, p. 444), and which are shorter than the true cystidia and 

 thin-walled, and probably do not exude the contents through the dis- 

 solved apex as generally do the cystidia. Massee calls these cells 

 "marginal cells." In addition to these sterile cells, many species of 

 Inocybe bear typical cystidia on the edge of the gills, Avhile some 

 species have them only on the surfaces, and in the case of a few, 

 like I. paludinella Pk., the edge of the gills is so thickly beset 

 with the genuine thick-walled cystidia that the " sterile cells " are 

 almost always obscured. Massee's statement that the larger " mar- 

 ginal cells," which I am calling true cystidia, are always thin-walled, 

 must therefore be set aside, since I have observed typical thick- 

 walled cystidia on the edge of the gills of a large number of species. 



