MURRILL : POLYPORACEAE OF NORTH AMERICA 641 



more or less zonate surface, which may be glabrous or variously 

 adorned with hairs. White or yellowish colors prevail for both 

 surface and context, only a few species showing light-brown or 

 gray tints. The hymenium becomes wholly or partially fuscous 

 in a few species, but it is generally white. The tubes are small 

 and delicate, often breaking up with age. In some species there 

 is an early fission of the dissepiments and the hymenium becomes 

 irpiciform, as in the very common Coriolus pargamcmts. 



Work in this entire group has been rendered exceedingly diffi- 

 cult by the large number of "new species" published inde- 

 pendently in former years from three or four European centers of 

 research, each ignoring the existence of the rest. In the case of 

 the present genus, these brief early descriptions are entirely in- 

 adequate and the poorly preserved type plants, when they exist at 

 all, often fail to supplement them sufficiently. 



Add to this the host of incorrect determinations found in the 

 literature then current, the wholesale assignment of foreign names 

 to plants exclusively American, and the glittering array of species 

 in important herbaria combined under one name, and the system- 

 atist confronts a set of conditions unusually stringent where 

 plants naturally closely allied are to be distinguished and new 

 species described. 



Synopsis of tbe >orlli American species 



1. Tubes more or less entire, at least until the sporophore is quite old. 2. 

 Tubes soon breaking up into long irpiciform teeth. 24. 



2. Surface of pileus wholly or partly glabrous when mature or clothed only with incon- 



spicuous hairs. 3 



Surface of pileus clothed entirely with a very conspicuous hairy covering. 18. 



3. Pileus not entirely glabrous at maturity. 4- 

 Pileus entirely glabrous at maturity. 10. 



4. Pileus marked at maturity with glabrous zones of a different color from the rest 



of the surface. 5- 



Pileus not marked with glabrous zones, but nearly uniform in color and not shin- 

 ing. 9- 



5. Glabrous zones large, numerous, conspicuously and variously colored. 



I. C. versicolor. 

 Glabrous zones small and comparatively inconspicuous. 6- 



6. Surface villose between the zones, which are late in appearing ; plants small, 



1-2 cm. in diameter. 2. C. hirsutulus. 



Surface minutely pubescent or tomentose between the zones ; plants usually much 

 larger. 7- 



7. Hymenium white or yellowish. 8. 

 Hymenium fuscous. 3. C. fiori Janus. 



