now .in the Delessert Herbarium at Geneva. 7 Next, Hexagona tenuis, the 

 most common species of the tropics was named by Hooker from South America. 

 The specimen is in fair condition in Hooker's herbarium at Kew. Then Per- 

 soon published Hexagona apiaria and Hexagona vespacea from the island of 

 Rawak, and both are in good condition at Paris, the latter rather scanty however. 

 When Fries issued his Epicrisis (1838) twelve species were supposed to be 

 known and Fries had overlooked one of Palisot's. 8 Since the Epicrisis there 

 has been a steady output of "new species." There are in my index 125 names 

 of supposed species, but this includes a few that were not called Hexagona 

 but which in my opinion should have been, and a larger number that were called 

 Hexagona and should not have been. 



The work in this pamphlet. In my work with the polyporoids I have visited 

 and studied and photographed the species of Hexagona in the following museums : 

 Kew London, British Museum London, Leiden, Berlin, Upsala, and Paris, 

 and the private herbarium of Monsieur Patouillard at Paris. Most of the 

 historic material is preserved in these museums and of the 125 species named 

 in my index I have seen the type (or in a few cases the co-type) of all that 

 exist but eight. 



Classification. For convenience we arrange the species in sections 

 or groups. We have tried to make these groups as natural as possible 

 for the benefit of the future ."new genus" discoverers. 



First (Setosus). Typically the surface is clothed with dense, coarse, 

 branched, rigid hairs, usually detersive and then the surface is fibrillose. We 

 include also species which are covered with agglutinate fibrils generally with 

 free ends. 



Second (Velutinus). Surface covered with fine, soft pubescence, or veluti- 

 nate hairs. Plants that we include here are all thin and as to shape belong 

 in section 5 (Tenuis). A few species that are pubescent we arrange on general 

 relations in other groups, viz. : Pobeguini in Applanatus ; macrotrema in Pal- 

 lidus ; bipindiensis in Pseudofavolus. 



Third (Ungulaformis). Thick, hard, with long pores and generally hoof- 

 shaped. This section corresponds to the woody (Fomes) section of Trametes 

 and might be called Hexagona-Fomes. We include here also Hexagona resin- 

 osus on its general nature, although it has a pale context and might be placed 

 in the group Pallidus. 



Fourth (Applanatus). General shape applanate or flattened as distinguished 

 from Ungulaform or hoof-shaped. Plants of this section are of a softer nature 

 than the previous section. We include here for this reason Hexagona amplexens, 

 that from its shape alone should be included in the preceding, and for a similar 

 reason we include in the preceding resinosa which from its shape alone belongs 

 in this section. 



Fifth (Tenuis). Pileus very thin, rarely two or three mm. thick with small 

 (for Hexagona) regular, shallow pores. Surface smooth. We include in 

 Velutinus species with pubescent surface. 



Sixth (Pallidus). Context white or pale ochraceous. (All the preceding 

 except resinosus have context that is more deeply colored, ferruginous, cinna- 

 mon, etc.) 



Seventh (Pseudofavolus). All the previous have context suberose or sub- 

 ligneous. In this section we include the species with fleshy, tough nature. 

 Usually they have been classified with the genus Favolus from which they differ 

 essentially in their pore shapes. Patouillard bases on them a genus (Pseudo- 

 favolus). In our opinion, they should be included in Hexagona. 



'I have never s<een these, but Palisot gave such fine illustrations that it is not necessary 

 to see them. One can be as sure from such illustrations as from the specimen itstlr. 



8 Viz: Hexagona glabra. As Saccardo seems to have started his compilation of the poly- 

 poroids with Fries's 1 Epicrisis, this species does not occur and has been lost to all modern books. 



