1925] 



~ BURT THE THELEPHORACEAE OF NORTH AMERICA. XIV 239 



of basidia as a transversely septate cystidium should lead to the 

 ready recognition of this species when sectional preparations are 

 studied. 



Specimens examined: 

 Florida: Cocoanut Grove, R. Thaxter y 57, type (in Mo. Bot. 



Gard. Herb., 43947). 



23. P. exilis Burt, n. sp. 

 Type: in Mo. Bot. Gard. Herb. 



Fructifications longitudinally effused, very thin, closely adnate, 

 pale olive-buff, even, somewhat velutinous, the margin thinning 

 out, indeterminate; in section 30-60 \l thick, not colored, com- 

 posed of erect, bushy-branched hyphae 3 \t, in diameter, ascending 

 from the substratum, soon terminating in basidia and cystidia, 

 not nodose-septate, with very little, if any, incrustation; no 

 gloeocystidia; cystidia hair-like, irregular, flexuous, 30 X 4J/- 



5 pi, protruding up to 20 [l, few and scattered; basidia simple, 

 with 4 short sterigmata; spores hyaline, even, 4^-5 X 23^-3 p. 



Fructifications 1-6 cm. long, about 1 cm. wide. 



On bark of decaying branches of frondose species in moist 

 virgin forest. Mexico. January. 



The fructifications of P. exilis occur as a thin, downy, gray 

 coating on very rotten branches 1-2 cm. in diameter. The pale 

 olive-buff color should be helpful in separating this species from 

 the great number more white in color. 



Specimens examined: 

 Mexico: Guernavaca, W. A. & E. L. Murrill, 385, comm. by 



N. Y. Bot. Gard. Herb, (in Mo. Bot. Gard. Herb., 54467); 



Orizaba, W. A. & E. L. Murrill, 757, type, and 780, comm. by 



N. Y. Bot. Gard. Herb, (in Mo. Bot. Gard. Herb., 54619, 



54620). 



24. P. livida Fries in herb, under Corticium, n. sp. 

 Peniophora serialis in part of v. Hohnel & Litschauer, Bourdot 



6 Galzin, and Rea. Not Corticium seriate Fries of Fries Herb. 

 Not Xerocarpus Cacao Karsten, Hedwigia 29: 271. 1890. 



Type: in Herb. Fries, determined by E. Fries as Corticium 

 lividum. 



