252 



or bristly, with a distinct ostioluin. The asci are cylindrical, eight spored. 

 Spores continuous, broadly ovate, elliptical, oblong or fusiform, brown or 

 black, with or without hyaline appendages. Paraphyses filiform. Stroma 

 tomentose, often wearing off with age and exposing the perithecia as 

 round, brownish black heads with their papilla-like ostiola in the center. 



In studying the species of Bosellinia we are confused at times when we 

 find forms which closely resemble certain forms of the genus Hypoxylon. 

 In such cases a clear distinction seems impossible, yet these two genera 

 are clear cut in their separation by botanists, being separated on the 

 ground of the presence of a stroma in Hypoxylon, and tbe absence of a 

 distinct stroma in Rosellinia. To anyone that has made a study of either 

 of these two genera, the superficiality of this basis of separation is quite 

 evident. Students of the genus Hypoxylon know that the pei'ithecia of 

 certain forms become scattered, and especially with age, the stroma is 

 wanting. 



The genus Rosellinia is placed under the Sphceriaeece by both Lin- 

 dan and Ellis and Everhart. This separates it widely from Hypoxylon. 

 Saccardo puts it under the brown spored one-celled forms of Xylariacew 

 along with Hypoxylon. The author likes this position on account of the 

 great similarity of spores, asci and perithecia, as well as the above men- 

 tioned similarity of forms where the absence of stromata is noticeable. 



Variation within a given species often makes it almost impossible to 

 formulate a key that will hold in all cases. In order to eliminate this dif- 

 ficulty the species are made to run in two ways. The species R. siibiculata 

 for example has in the earlier stage a decided waxy sulphur-yellow 

 subiculum and the perithecia are scattered, but as it grows older the 

 subiculum finally disappears so that one might readily confuse it with 

 other species that never have a subiculum. The ascis and spore measure- 

 ments are probably the most constant and reliable in forming a basis 

 for a key. The second key, it is hoped, will prove helpful in determining 

 any doubtful species that do not run satisf acorily in the key of external 

 characteristics. 



The accompanying figures from photographs will assist in deterimining 

 the species. In order to get the greatest contrast possible, time ex- 

 posures were made in a subdued light and a special contrast developer 

 was used. 



The description of species have been adapted for the most part from 



