106 
Mycologia 
the partly matured spore often taking the form of reticulations, 
the ridges becoming more pronounced about the periphery of the 
spore until at maturity they appear echinulate with the spines 
connected by the broken and interrupted ridges mentioned above. 
The intermediate forms were not seen in the Maine plant for lack 
of material. All at maturity are pale yellowish-brown. 
From the above observations it is evident that we have three 
plants with spores which are, so far as I am able to determine, 
identical, i. e., Boudiera areolata Cooke & Phill., Sphaerosoma 
echinulatum of the writer and the unnamed plant collected by 
Dr. Thaxter in Maine. From the gross characters, however, I 
would not suspect that Dr. Thaxter’s plant is the same as my own. 
The plants in the former are smaller, subturbinate, with the 
hymenium convex and asci strongly protruding. In the latter the 
plants are larger, flattened below, with the hymenium forming 
almost a complete semi-circle and the protruding asci not evident, 
although it is possible that this latter character might have been 
overlooked in the Iowa plants. When we take into consideration 
the fact that only five plants were collected in Maine and several 
hundred in Iowa, it is possible that these apparent differences in 
gross characters might fade out if the eastern plant could be col- 
lected in larger quantity. 
Dr. Thaxter’s plants accord more closely with early illustrations 
of Boudiera areolata Cooke & Phill. than do my own. However, 
after studying part of the type of B. areolata the writer is con- 
vinced that Sphaerosoma echinulatum is only an American form 
of Boudiera areolata of European authors. That this is a Euro- 
pean species is evident from the fact that the species has been 
collected twice in Europe since its description from Iowa material, 
but each time it has been referred to t'he name given to the Ameri- 
can plant with no suggestion that it had been previously described 
in Europe. The illustration of Boudiera areolata by Boudier 8 fits 
Sphaerosoma echinulatum so far as gross characters and color are 
concerned. The section, however, shows the hymenium as occu- 
pying the upper surface only and in this it does not agree with the 
A. echinulatum. This sketch, however, may be diagrammatic. 
The habitats of three collections also show a striking similarity. 
The European plant was originally collected by William Phillips 
8 Boudier, Ic. Myc. pi. 417. 1909. 
