136 Forty-second Annual Report on tee 



arrangement of the species, dividing them into two groups, the 

 Orcelli, distinguished by deeply decurrent lamellae and an irregular, 

 scarcely hygrophanous pileus, with the margin at first flocculose; and 

 Sericelli, distinguished by adnate or slightly decurrent lamellae, and a 

 regular silky or hygrophanous-silky pileus with a naked margin. This 

 arrangement is not strictly applicable to some of our species. G. abor- 

 tivus, G. erythrosporus and G. Noveboracensis have the lamellae deeply 

 decurrent in some individuals, adnate or slightly decurrent in others, 

 and therefore the same species might be sought in both groups. For 

 this reason, the primary grouping of our species has been made to 

 depend on the variation in the spore colors. By far the greater 

 number of our species appear to be peculiar to this country, only two 

 of them occurring also in Europe. 



Synopsis of the Species. 



Spores and mature lamellae flesh-colored 1 



Spores and mature lamellae rosy-red 9 



Spores very pale flesh-colored 10 



1. Pileus hygrophanous , 8 



L Pileus not hygrophanous 2 



2. Pileus gray or grayish-brown 5 



2. Pileus some other color 3 



3. Pileus white or whitish • • • 4 



3. Pileus pale tan-color G. pascuensis. 



4. Pileus firm, dry, pruinate G. prunulus. 



4. Pileus soft, slightly viscid when moist G. Orcella. 



5. Pileus large, more than 1.5 in. broad , C. abortivus. 



5. Pileus small, less than 1.5 in. broad 6 



6. Spores even .- G. unitinctus. 



6. Spores angular , 7 



7. Stem longerthan the width of the zoneless pileus .... G. albogriseus. 

 7. Stem shorter than the width of the commonly 



zonate pileus G. micropus. 



8. Pileus brown or grayish brown G. submits. 



8. Pileus white or yellowish-white G. Woodianus. 



9. Stem colored like the pileus G. erythrosporus. 



9. Stem white, paler than the pileus G. conissans. 



10. Pileus even 11 



10. Pileus rivulose. G. Noveboracensis. 



11. Stems caespitose, solid G. ccespitosus. 



11. Stems not caespitose, hollow G. Seymourianus. 



