TROPICAL POLYPORES 31 



i. RIGIDOPORUS MICROSTOMUS (Berk. & Curt.) Murrill 



Pileus effused, laterally connate, very shortly reflexed, 1-4 X 

 1-1.5 X 0.2-0.4 cm - tne reflexed portion very narrow, laterice- 

 ous, finely pubescent to glabrous, faintly zonate, with a thin, 

 undulate or slightly lobed, yellowish-white margin; context very 

 thin, white, fibrous; tubes long and slender, 2-3 mm., white 

 within, mouths minute, 7 to a mm., ochraceous or flesh-colored, 

 edges obtuse, entire. 



Found once on dead wood in Cuba. 



2. RIGIDOPORUS EVOLUTUS (Berk. & Curt.) Murrill 



Pileus fleshy-tough, circular to flabelliform, 1-2.5 cm - broad, 

 1-2 mm. thick; surface radiate-rugose, tomentose to resinous- 

 glabrous, latericeous with ochraceous blotches, black behind; 

 margin thin, acute, undulate to slightly lobed, ochraceous; 

 context very thin, pallid, fibrous; tubes pallid, 1-1.5 rnm. long, 

 mouths minute, 7 to a mm., subcircular, edges white to yellowish- 

 discolored, thin, dentate. 



Found once on dead trees in Cuba, and once on dead wood in 

 the mountains of Porto Rico. 



3. RIGIDOPORUS SUBSTEREINUS Murrill 



Pileus thin, coriaceous, inflexed when dry, dimidiate, attached 

 by a narrow base, applanate, 1-3 X i-5~5 X 0.1-0.2 cm.; surface- 

 smooth, shining, glabrous, conspicuously zonate, radiate-rugose,, 

 latericeous to bay with isabelline lines, much resembling SL 

 Stereum; margin very thin, smooth, cremeous, broadly sterile 

 below, sharply inflexed on drying; context exceedingly thin, 

 white, fibrous; tubes minute, 0.5-1.5 mm. long, white to pallid 

 within, mouths very even, regular, angular, inconspicuous, 6-7 

 to a mm., edges thin, entire, whitish-pruinose to ochraceous or 

 pale-flesh-colored . 



Occasional on dead sticks in woods in Cuba, British Honduras, 

 and eastern Mexico. 



4. RIGIDOPORUS LIEBMANNI (Fries) Murrill 



Pileus fleshy to woody, thin, flabelliform or obovate, convex, 

 1.5-2 X 2-3 X 0.2-0.4 cm.; surface glabrous, bay or blackish, 

 often rugose behind; margin thin, entire, pallid, sterile, inflexed 

 when dry; context very thin, white, fibrous, brown and very 

 fragile in type specimens; tubes slender, 1-1.5 mm. long, white 

 to pallid within, mouths whitish-pruinose to yellowish-brown, 



