PILACEE. 47 



PILACREAB. 



The present group, established by Brefeld, is ia every 

 i;espeot an6'm3,loTis, and in reality appears to occupy a tran- 

 sitional position between the Gastromycetes and the Hyme- 

 nomycetes. The single genus, Pilacre, consists of minute 

 fungi rarely exceeding half an inch in height, and resembles 

 a long-stalked puffball, or rather a Tulostoma in miniature, 

 consisting of a more or less globose head supported on a 

 slender stem. The stem is continued into the head or gleba 

 as a compact, subglobose columella, from which spring a 

 large number of hyphae that produce clusters of basidia. 

 These basidia agree with those met with in the sub-Family 

 Auricularieae of the Tremellineae in being cyKndrical and 

 transversely septate ; this feature is considered by Brefeld as 

 indicating an affinity with the Tremellineae, from which the 

 species differ widely in every other particular. The mass of 

 basidia-producing hyphae, along with others that are sterile, 

 are at first enclosed in an outer weft of hyphae that may be 

 compared with the peridium in the Gastromycetes ; in fact, 

 the reproductive portion is at first concealed in a peridium 

 that eventually disintegrates, a character that suggests 

 affinity with the Gastromycetes. Nevertheless, the above 

 account shows that the group under consideration is not 

 typical of either of the above-named groups, hence its present 

 intermediate position. 



In Saccardo's Sylloge the genus is placed in the Hyphomy- 

 cetes ; this, however, is the outcome of mere superficial resem- 

 blance, and directly opposed to all morphological characters. 



PILACEE. Fries, (figs. 1, 2, 3, p. 48.) (emended). 



Peridium subglobose, stipitate, wall single, fibrillose, at 

 length evanescent ; stem continued into the gleba as a colu- 

 mella, from which originate numerous hyphae that produce 

 lateral branches terminating in 1-4 transversely septate, 

 cylindrical basidia, and usually terminate in sterile, spirally 

 twisted branchlets; spores coloured, circular in outline^ 



