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or bristly, with a distinct ostiolum. 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 Rosellinia 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 the 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 perithecia of 
certain forms become scattered, and especially with age, the stroma is 
wanting. 
The genus Rosellinia is placed under the Spheriacew 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 Aylariaceew 
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. subiculata 
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 satisfacorily 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 
