103 



less at the mouth than it is a little distance above. The hymenial 

 surface appears very much as if it had been thinly overspread by 

 some colored, yielding but inelastic substance, and then punctured 

 by the point of a pin just over each pore. The prominence of the 

 interspaces causes the pores to appear as if in little depressions. Are 

 the characters now noticed of generic value? Possibly some may so 

 regard them ; and, certainly, genera of fungi have been constituted 

 upon far less obvious characters than these ; but until other species 

 are known which shall give emphasis to the importance of these char- 

 acters it seems best to me to consider them merely sectional or at 

 most subgeneric. Without them the species would naturally fall in 

 the Suberose section of the Placoilennei. In this section is the birch 

 Polyporus^ {F, betulinus^ a species in which also the margin of the pjl- 

 eus extends beyond the mouths of the pores, but to a far less extent. 

 It never even partially conceals them from view. In this species 

 also, the pores and a very thin layer of the hymenophore to which 

 they are attached are separable in the fresh plant from the main part 

 of the pileus. Thus it makes an approach to the aberrant characters 

 oi P, volvatus ; slight, indeed, but sufficient to indicate the relation- 

 ship of the latter to more typical Polypori and to cast a doubt upon 

 the generic value of the characters indicated. That the mouths of 

 the pores should present a color unlike the rest might not, of itself, 

 be considered a very important or novel feature, but the permanent 

 thickening of the dissepiments at this place and the consequent dim- 

 inution here of the diameter of the pores is a character not clearly 

 shown by any other Polyporus known to me. It may, therefore, be 

 well to make at least another section of the Placodermei for the re- 

 ception of this fungus. 



The typical form of the species has been found on dead trunks of 

 the black spruce, Abies 7iigra. It occurs on these plentifully in some 

 parts of the Adirondack forests of New York, where it follows the de- 

 vastating track of the spruce-destroying beetle. Dozens of speci- 

 mens may be found on the trunk of a single tree, and generally each 

 specimen covers a perforation previously made in the bark of the 

 tree by the attacking beetle. The mycelium grows beneath the bark 

 and the perforations afford a convenient passage-way to the external 

 air where the fungus is developed. Any crevice in the bark, how- 

 ever, will answer the same purpose, so that the fungus is not depend- 

 ent on the perforations of the beetle for its full development and the 

 continuance of its species. The average size of the specimens is 

 from one-half to three-fourths of an inch in diameter. Rarely do 

 they exceed one inch in diameter. The color of the mouths of the 

 pores is a pale cinnamon-brown. 



A second form has been collected in California by H. W. Hark- 

 ness, M.D., who finds it on the twisted pine, Finns contorta^ and on 

 one or two other coniferous trees. A single S2:)ecimen was once found 

 by the writer. It grew on pitch pine, Finns rigida^ near Albany, 

 New York. This form is generally larger than the other, its average 

 diameter being about one inch. The mouths of the pores are also 

 generally darker colored. Specimens of it were sent to England and 

 there received the name Polyporus obvolntus Berk, and Cke., {Grev- 



