THALLOPHYTES 87 
coming to the surface, after having broken through the epidermis. These 
basidia, each bearing four spores, arise directly from the mycelium, without any 
complex sporophore formation, differing in this respect from the following groups. 
(g) Thelephorales 
The sporophores of these forms appear on tree trunks as flat and tough leathery 
incrustations, the hymenium spreading over the smooth upper surface ; or as 
brackets raised above the substratum, the hymenium extending over the under 
surface; or as funnel-shaped bodies lined with the hymenium. The general char- 
acter of the sporophore distinguishes this group from the next ; and the indefinite 
extent of the hymenium over the sporophore distinguishes both groups from those 
which follow. 
(h) Clavariales 
These are the coral fungi, with fleshy sporophores that often simulate branching 
coral in form, the hymenium covering the whole surface of the branches. There 
are also unbranched, club-shaped sporophores ; but all are characteristically 
fleshy and hymenium-covered. 
(i) Agaricales 
This is by far the greatest group of fleshy fungi, containing most of 
the so-called mushrooms and toadstools. The complex sporophore is 
FIG. 197. Lepiota : a common edible mushroom. After COULTER. 
usually definite in form, being differentiated into stipe and pileus (fig. 
197), the latter having special surfaces for the hymenium. The prin- 
cipal families are as follows : 
