250 PROCEEDINGS OF THE AMERICAN ACADEMY. 



In these forms the very young perithecium can be readily distin- 

 guished from the bulbil, not only by its mode of development when 

 that is different, but also by the color. The bulbils turn brownish 

 at a very early stage in their development, such as is represented, 

 for example, in Figure 2, Plate 2, while on the other hand, the peri- 

 thelia frequently remain colorless, or nearly so, until they are beyond 

 the size of the average mature bulbil, and the ascogonium usually can 

 be distinctly seen in the form of one or two large cells lying towards 

 one side of the young perithecium. 



The question of sexuality in connection with the formation of the 

 ascogenous primordia has nut been worked out. Structures have been 

 observed that might well be taken for antheridial branches, but their 

 attachment was not constantly or certainly observed, so that this 

 phase of the problem will have to be left for future consideration. 



Among the twenty bulbil cultures from different sources which have 

 been found by the writer to produce melanosporous perithecia, at 

 least three distinct species appear to be distinguishable. Although 

 these forms possess ascospores that show little if any variation, the 

 differences in their perithecia, bulbils and secondary spore-forms are 

 such that they cannot be included in a single species. Moreover, the 

 characteristics are believed to be sufficiently distinctive to warrant 

 their consideration as separate species. They have then Ion- been 

 named Melanospora papillata, M. cervicula, and M. anomala. There 

 thus appear to be several closely related Melauospora-like forms, in- 

 cluding Sphaeroderma bulbilliferum, Melanospora Gibelliana and M. 

 globosn all of which give rise to bulbils. 



The differences which distinguish the perithecia of these forms may 

 be summarized as follows: 



Melanospora Gibelliana; neck of perithecium long and tapering, 

 with terminal setae, asymmetrical ascospores. 



M. globosa; neck of perithecium longer than M. Gibelliana, no well- 

 defined terminal setae, symmetrical ascospores. 



M. papillata, n. sp. ; perithecium with a distinct papilla only with 

 terminal setae, asymmetrical ascospores. 



M. cervicula, n. sp.; perithecium with a short neck, terminal and 

 lateral setae, asymmetrical ascospores. 



M. anomala, n. sp.; perithecium more or less definitely papillate, 

 with occasional indications of abortive terminal setae, asymmetrical- 

 ascospores. 



Sphaeroderma bulbilliferum; perithecia without papillae or setae. 

 The species of "Sphaeria "mentioned by Biffen as associated with 

 Acrospeira mirabilis and the species of " Ceratostoma " connected 



