OVERHOLTS: DIAGNOSES OF AMERICAN Portas—II 247 
as seen in PLATE 13, FIG. 6; and this type grades over into a 
more heavily incrusted form, as represented in PLATE 13, FIG. 7, 
where they have the form and appearance of those found in 
Fomes connatus. Indeed, in the absence of spores, I had prev- 
iously referred specimens of this type to a resupinate con- 
dition of that species. 
The close microscopic agreement of all the plants with these 
variable structures and with other characters mentioned below, 
and the gradations and apparent relationships of these structures 
themselves seem to imply a relationship that can be readily 
embraced within the limits of a single species. About the only 
other American plant that shows cystidia comparable to those 
of the European P. corticola is P. aurea Peck, which seems to 
differ sufficiently in the shape and size of the spores, the presence 
of clamp connections, and other features, to warrant keeping it 
distinct. 
Nearly all of the specimens I have referred to this species 
have another peculiar microscopic character in the tendency of 
the spores to cohere in groups of two to four (TEXT FIG. 1). 
The hyphae are also more or less distinctive in the presence 
of occasional distinct cross walls without clamp connections. 
The variability of the species will make it difficult to recognize 
at times. The essential characters seem to be the soft white 
plant widely effused on hardwoods, the tubes well developed, 
the hyphae with rather frequent cross walls (TEXT FIG. 1), 
and in addition one or more of the following characters: (a) well- 
developed hyaline projecting unincrusted cystidia; (b) capitate- 
incrusted paraphyses (?); (c) heavily incrusted irregular pro- 
jecting cystidia; and (d) ellipsoid spores cohering in small 
groups. 
PorIA INERMIS Ellis & Everhart, Proc. Acad. Nat. Sci. 
Philadelphia 1894: 322. 1894 
Original Description: Resupinate, adnate, seriate, extendin 
nad sai lim BIE 6 in. or more and about 1 in. wide, y ac a 
ick in the middle, margin thie. narrow, 
light eile (wes fresh), and closely adnate; pores small, round, 
extending down to the underlying ia eis s ferruginous, 
