﻿1903] 



BRIEFER ARTICLES 



43^ 



scopic structure. It is less roughened externally than the typical form 

 of 7: riiftim, and is distinguished from both of the species named by the 

 color of the gleba and spores, by the more conspicuous veins, by the 

 more densely crowded asci, by the slightly larger size and more elon- 

 gated form of the spores, and apparently also by the greater extent 

 of the scar-like external opening of the venae externae. 



Tuber Lyonin.sp, — Ascoraataglobose or irregularly elliptical, 0.5-2^'" 

 in diameter, having a distinct scar-like groove along one side, smooth, 



Fig. 3. — A^^ typical four-spored ascus; .5, an irregular four- 

 spored ascus ; C^ a one-spored ascus, X ^50- 



light chestnut-brown, becoming finally very minutely 

 areolate and blackish. Peridium not thick, cartilaginous. Gleba 

 violaceous brown, fleshy but somewhat granular. Septa arising from 

 the peridium, numerous, anastomosing, labyrinthiform, dark trans- 



lucent. 



Venae externae white, conspicuous, opening externally 



throughout the length of the groove. Asci pedicellate, 1-5- mostly 

 4-spored. Spores elliptical, acutely echinulate, 15-31 X25-4S /x. 

 Type specimens are deposited in the Herbarium of the University of 

 Minnesota. 



The occurrence of this form in Minnesota suggests that it is very 

 possible that this and other species of tuberaceous fungi are not 

 uncommon in the interior of North America. The conditions of their 



growth render their discovery almost entirely a matter of accident, and 

 in the case of Tuber Lyoui the peculiar season at which it occurs may 

 further account for the fact that it has not been hitherto discovered. 

 Fred K. Butters, University of Minnesota, 



