7 2 FUNGI IMPERFECTI 



5. Pycnidia shield-shaped, separating readily; basidia obsolete. 



LEPTOTHYRIUM. 



Pycnidia irregular ; basidia columnar. PIGGOTIA. 



Pycnidia irregular ; basidia obsolete. MELASMIA. 



Entomosporium (PL j, f. 4), so-called from the resemblance of 

 the ciliated spores to insects, is a common parasite of pears and 

 quinces ; a species of Piggotia is more or less abundant on the ash; 

 and a species of Melasniia is found on the American elm. 



The EXCIPULACEAE are cup-shaped or lenticular, either membra- 

 nous or carbonaceous, smooth or pilose ; in exceptional genera the 

 pycnidia are more or less elongate, simulating species of the Hyster- 

 iaceae. Twenty-two genera are known, most of which are small, 

 except Excipuhi and Dinemosporium with one-celled hyaline 

 spores, the former with smoothish pycnidia and the latter with 

 pilose pycnidia and spores ending in a bristle. (PL j. /. 5.) Both 

 the genera named are among the few containing leaf-parasites. 



LITERATURE. 



Saccardo. Sylloge Fungorum, 3: 3-695; 10 : 100-444; n : 472- 

 561. 



Martin. The Phyllostictas of North America. Jour. Mycol. 

 2 : 13-20, 25-27. 1886. 



- Enumeration and Descriptions of the Septorias of North 

 America. Jour. Mycol. 3 : 37-41, 49-53, 61-69, 73-82, 85-94. 

 1887. 



Allescher. Rabenhorst's Kryptogamen Flora Deutschlands, 

 u. s. w. i 6 : i- . 1898. (Current.) 



The parts of Die natiirlichen Pflanzenfamilien relating to the 

 Fungi I m perfect! have not yet appeared. 



Order 2. MELANCONIALES. 



The order Melanconiales contains a single family, the MELAN- 

 CONIACEAE, made up of a comparatively small number of species 

 in which neither asci nor pycnidia are developed. As a rule the 

 spores are borne in cavities without special walls, often rising 

 from little masses of short hyphae. The greater number of the 

 species are saprophytic on decaying vegetable substances but a 

 few are parasitic and occasion a number of destructive diseases, 



