486 Durand : Classification of the Fleshy Pezizineae 



of the excipulum, however, is different, being composed of rounded, 

 thin-walled, hyaline cells, 10—15 fi in diameter. 



Review of the Helotiaceac. — It will be noted that in all the 

 Helotiaceous plants described above the principal tissue is a pro- 

 senchyma composed of long-drawn-out, slender hyaline hyphae 

 closely interwoven. In the greater number, especially of the 

 stipitate forms, it is the only tissue present. In all, it fills the 

 medullary part of the stem and cup. In a few forms there is a 

 cortical layer of pseudo-parenchyma but in the family as a whole 

 this tissue is comparatively rare. It seldom if ever forms the 

 margin of the cup, but is confined to the surface of the sides and 

 base. There is also a sharp line of demarcation between such 

 tissue and the prosenchyma, and rarely can one detect the much 

 septated and coalesced hyphae showing a transition to the cellular 

 structure, such as is commonly seen in the Pezizaceae. The 

 tissue, too, whether it be hyphal or cellular is always hyaline and 

 thin-walled. 



The hyphae in this family are very different in character from 

 those found in the Pezizaceae. Here they are always very slender, 

 long-drawn-out, but little branched, and infrequently septated. In 

 the Pezizaceae they are stout, strongly curved, branched, and 

 usually much septated. In the majority of cases in the Helo- 

 tiaceae the ectal excipular layer forms a sort of cortical membrane 

 covering the surface of the cup. 



Family MOLLISIACEAE 



Mollisia cinerea (Batsch) Karst. PI. $2, Fig. 14 



This is a very common little Discomycete growing on rotten 

 wood, especially in the spring. The cups are sessile and soft- 

 waxy, with a cinereous disc. 



The excipulum consists of two layers. The inner one with the 

 hypothecium fills the medullary portion of the cup beneath the 

 hymenium and extends upward to form the margin. It is com- 

 posed of very delicate, hyaline hyphae. At the base and side of 

 the cup, this gives place to a pseudo-parenchymatous outer excipu- 

 lar layer composed of rounded cells, 9-12// in diameter. The 

 walls of the innermost cells are hyaline, but those near the surface 



