424 MuRRiLL : Polyporaceae of North America 



mouths of the pores and wholly or partly concealing them from 

 view, generally opening beneath by a small aperture ; pores not 

 stratose, the dissepiments thickened at the mouths and there dif- 

 ferently colored." 



In raising this section to generic rank, Shear cites Peck's de- 

 scription and the description of the single species contained in the 

 section following, with a brief discussion of varieties and several 

 additional collections from new localities. 



Cryptoporus volvatus (Peck) Shear 



Polyporusvolvahis Peck, Rep. N. Y. State Mus. 27 : 98. 1877. 



Polyporiis obvolut2is Berk. & Cooke, Grevillea, 7: i. 1878. 



Fomes volvatus Cooke, Grevillea, 13: 119. 1884. 



Cryptoporus volvatus Shear, Bull. Torrey Club, 29 : 450. 1902. 



This peculiar plant was described from specimens collected on 

 Abies nigra. It is also found rarely on Abies halsaniea, but seems 

 to prefer species of pine, upon which it is quite common. I have 

 seen dead trunks of Pinus rigida filled with the mycelium, the 

 fruit bodies emerging through holes made by beetles. It is pos- 

 sible that the specimens found on charred wood in the West are 

 larger than our Eastern plants because no effort is required to 

 reach the surface through a heavy layer of cortex. Torrey's stip- 

 itate Western form figured by Gerard is duplicated at times in the 

 East when the plant grows on the top of a log. Henning's variety 

 Helix from California is fully described by Peck and differs in no 

 way from the type, which had not been seen when the variety was 

 described. Peck's varieties obvoliitus and Torreyi seem hardly 

 worthy of separation. P. evolvens Berk. & Cooke, Herb. Berk. 

 1879 from California, fastened to a sheet of P. evolutus B. & C, 

 is only P. volvatus and is very distinct from P. evolutus. 



Exsicc. : California, Harkness, Torrey, McClatchie ; Colorado, 

 Crandall, Shear & Bessey ; Oregon, Shear, Carpenter; West Vir- 

 ginia, Nuttall ; New York, Murrill ; Michigan, Robbins ; British 

 Columbia, Macoun ; Delaware, Commons ; District of Columbia, 

 Shear, Hicks. 



PiPTOPORUS Karst. Rev. Myc. 3: 17. 1881 

 This genus was originally established upon a single species, 

 Polyporus betulinus (Bull.) Fr., and has since remained monotypic. 



