1925] 



BURT THE THELEPHORACEAE OF NORTH AMERICA. XIV 243 



stain, such as is more distinctly visible, because coarser, in P. 

 phyllophila, Hypochnus pallescens, Corticium investiens and 

 Grandinia granulosa, and whose peripheral branches are more or 

 less visible in the surface of the hymenium as antler-shaped 

 paraphyses. P. mexicana has coarser hyphae and more hypoch- 

 noid surface. 



Specimens examined: 

 Porto Rico : Martin Pifia, Rio Piedras, J. R. Johnston, 971 a, type 



(in N. Y. Bot. Gard. Herb., Mo. Bot. Gard. Herb., 63243, and 



Burt Herb.). 



27. P. mexicana Burt, n. sp. 



Type: in N. Y. Bot. Gard. Herb, and Mo. Bot. Gard. Herb. 



Fructifications longitudinally effused, adnate, dry, hypochnoid, 

 thin, cream color in the herbarium, even, velutinous under a 

 lens, not cracked, the margin thinning out; in section 140 [l 

 thick, not colored, composed of even- walled, rather rigid, loosely 

 arranged, branching hyphae 5-7 ^ in diameter, not incrusted, 

 not nodose-septate, which ascend obliquely from the substratum 

 and bear a dense hymenium containing numerous cystidia and 

 branching, filiform paraphyses (or perhaps conidiophores) ; no 

 gloeocystidia; cystidia minutely incrusted or rough, tapering, 

 60-100 X 5-9 (A, protruding 40-60 [i; spores (perhaps conidia) 

 hyaline, even, 6-7J^ X 4-5 jx, copious. 



Fructifications 4 cm. long and broken off at both ends, 6 mm. 

 wide. 



In depressed places on very rotten frondose wood. Mexico. 

 January. 



The dry, cream color or buff fructifications of hypochnoid 

 texture, very coarse hyphae, large cystidia, and branching par- 

 aphyses or conidiophores in the surface of the hymenium are 

 characters which should make this species recognizable, although 

 my inability to demonstrate basidia convinces me that the type 

 is in a conidial stage somewhat comparable with that of Corticium 

 roseum. 



Specimens examined: 

 Mexico: Orizaba, Nuevo, altitude 3600 m., W. A. & E. L. Mur- 



rill, 773, type (in Mo. Bot. Gard. Herb., 54633). 



