196 Cincinnati Society of Natural History. 



young growing hynienium is velvety with a minute jnibescence, 

 but it is not setulose ; it becomes smoother and paler with age. It 

 is Thelephora albomarginaia. Berk, of Lea's Catalogue. 



11. S. DisciFORME, 1) C. Siibcoriaceous, white. Pileus 

 resupinate, determinate, discifor.n ; the border thin, free, naked, 

 marginate. Hymenium uneven, velvety. 



On elm branches ; rare. Forming round irregular white 

 disks scarcely half an inch in diameter, with the margin free and 

 raised up all around. The hymenium at first has a soft fine 

 pubescence. 



b. Pileus corky or woody, rigid. 



12. S. FRUSTULOSUM, Pcrs. Woody, resupinate, tubcrculose, 

 crowded and as if confluent, then appearing broken into small 

 pieces; the border absolutely marginate; around the edge and 

 underneath dark brown or blackish. Hymenium convex, cin- 

 namon becoming pallid, pruinose. 



On very hard oak wood ; common and abundant. The per- 

 fect hymenium facing the earth, at first pruinose, then ]nilverulent 

 with the cinnamon spores ; the part turned toward the light is 

 sterile, pale and smooth. The apparent frustules are irregular in 

 shape and of all sizes from half an inch in extent to minute frag- 

 ments. They spead over the cut surfaces and sawed ends ot the 

 hardest and driest White Oak logs. 



13. S. suBPiLEATUM, B. & C. Corky, rigid. Pileus effuso- 

 reflexed, zonate with concentric furrows, tay/ny changing to brown, 

 tomentose ; the margin undulate, obtuse. Hymenium even, jjallid 

 or whitish. 



On old trunks of oak ; common. Pileus 1-3 inches in breadth 

 and projecting half an inch or more, but often effused and confluent 

 to the extent of several feet. The large effused specimens are at- 

 tached to the substratum by rough knobs and j^rojecting points on 

 ihe underside. This is a larger and finer species every way than 

 .S' rugosum, Pers , to which it was first referred. 



14. S. CANDiDUM, Schw. Resupinate, rigid, thick, irregular 

 in outline, submarginate ; the margin and underside brownish. 

 Hymenium uneven, subpulverulenl, white. 



On [the bark of living trees, in winter; common. Half an 

 inch more or less in breadth. It forms small irregular white 

 patches upon the outer surface of the bark. There is scarcely any 

 margin. It is Thelephora candidissitna, Schw. N. A. Fungi, No. 



