GASTEROMYCETES 



479 



the spore powder. This genus also possesses a true capillitium (Fischer, 

 1884). 



Astraeus and Calostoma are sometimes placed in the Calostomataceae 

 in the Plectobasidiales on account of the more irregular arrangement of 

 their basidia. 



Tulostomataceae. — This family is characterized by the two-layered 

 peridium, rind-like on the outside, papery-firm within, and the irregular 

 gleba, penetrated by capillitium. As its development is as yet insuffi- 

 ciently investigated, the classification is only provisional. If the 

 assertion of Tieghem is confirmed (see also Schroeter), that their basidia 

 behave according to the stichobasidial type, they should be removed to 

 the Phleogenaceae. 



Tulostoma is the best-known genus, especially the cosmopolitan T. bru- 

 male and T. squamosum (T. mammosum) (Schroeter, 1876; Bessey, 1887; 



Fig. 305. — Tulostoma squamosum. A. Habit and section of fructification. B. 

 Median sections of fructification before and during elongation of stipe. C. Basidium. 

 (After Vittadini and Schroeter.) 



Petri, 1904). Their fructifications appear from fall to spring and lie 

 in the earth 2 to 3 cm. deep. They are laid down as small, sclerotial 

 swellings of the mycelium; the rind consists of compactly intertwined, 

 slender hyphae, the core of broad, short, inflated cells, barrel shaped in 

 the middle, between which run at large intervals, threads of thinner, 

 parallel- walled hyphae. The rind then differentiates into a brown 

 crust and a firm, papery interior. The core differentiates into a middle 

 and lower layer (Fig. 305, B). The core layer is approximately spherical. 

 It is loose in texture and remains white, even through the maturation 

 of the spores. The lower core layer is blunt, conical and consists of a 

 cylindrical column and covering. The column is composed of parallel, 

 slightly branched hyphae and forms the fundament of the later stipe. 

 The covering, consisting of tangled hyphae, dries after spore maturity, 

 leaving a small cavity between peridium and stipe at the base of the 

 fructification. 



