ORDER SPHAERIALES 275 



asci are digested and the ascospores escape in a mass of slime. Nannfeldt 

 (1932) therefore places the Chaetomiaceae in the group he calls Plecta- 

 scales, in this book called Aspergillales. His reason for so doing is that 

 there are no paraphyses or periphyses and that the asci dissolve into 

 slime. Closely related to the Fimetariaceae is the family Melanosporaceae, 

 also with thin perithecial walls, often but not always with a more or less 

 well-developed neck, and with ascospores mainly inclined to be dark- 

 colored and lemon-shaped as in most of the species of the two other 

 families. Neurospora and Gelasinospora probably belong here or in the 

 Fimetariaceae. The Melanosporaceae are often placed in the order 

 Hj^pocreales because of the almost colorless or light brown perithecia but 

 it seems best to place them here since the chief difference is only their 

 sometimes lighter color. (Fig. 90 C, D.) 



Family Fimetariaceae. The chief genera are Fimetaria {Sordaria) 

 and Schizothecium {Pleurage or Podospora) . Both are mostly found on the 

 dung of various animals. Some species have four-spored asci and others 

 asci with eight spores, while in a few species the number of spores is 

 much larger. In Fimetaria the spores are surrounded by a layer of water- 

 soluble slime on all sides except a small spot on one end. In Schizothecium 

 the spores are two-celled, one cell slender and empty and the other en- 

 larged and dark-colored. There is a long gelatinous appendage at each 

 end, sometimes several at one of the ends. Hypocopra is like Fimetaria 

 but the perithecia are immersed in a stroma, an exceptional case for this 

 group of families. (Fig. 87.) 



Family Chaetomiaceae. Chaetomium is the characteristic and most 

 frequently found genus of the Chaetomiaceae. Its long ostiolar hairs may 

 be stiff and straight, or wavy, or loosely or tightly coiled, depending upon 

 the species. The spores are mostly lemoru-shaped and dark-colored and 

 one-celled. The species are very numerous on damp straw, pasteboard, 

 etc., as well as on manure. Some species are destructive to cloth and other 

 vegetable fabrics, especially in the warmer and more humid portions of 

 the world. (Fig. 90 A, B.) 



Family Sphaeriaceae.^ Perithecia with firmer wall and with simple 

 ostiole or at most with a low papilla. Perithecia superficial on the sub- 

 stratum or sometimes on a felty mass of mycelium (subiculum). The 

 twenty or more genera in the family are mostly of little economic interest 

 except the genus Rosellinia. This deserves mention because of the wide- 

 spread occurrence of its species (over 200 are known from all parts of the 

 world), mostly on wood and bark. Several species are dangerous parasites, 

 e.g., R. necatrix (Hart.) Berl. on the roots and underground portions of 

 the stems of the grape (Vitis). The perithecia of Rosellinia are nearly 



^ See footnote on page 273. 



