40 THE GASTEROMYCETES OF THE UNITED STATES AND CANADA 



gelatinizing and early disappearing. Odor very strong, penetrating and peculiar, 

 quite unpleasant, nauseous, but with a somewhat fruity element like decaying apples 

 and very attractive to fruit flies, even in the dried condition. 



Spores smooth, elliptic, 3.9-4.2 x 7.4-8.4ju, with a hyaline cup at the proximal end. 



This species seems close to M . variegatus in certain characters, but it can be easily 

 distinguished in the fresh condition by the very striking and unpleasant odor. In 

 M . variegatus the spores are 2-5 on a basidium and are larger than in the present species. 

 The shape of the basidia is also quite distinct as shown by Tulasne's figures. The name 

 of M. odoratissimus suggests this plant but the odor of that is described as pleasant 

 while the odor of this is decidedly otherwise; the basidia of that plant are short and 

 distinctly swollen at the distal end, and the spores have a distinct long stalk (Hesse). 



The most important characters in distinguishing the present plant are the brownish 

 colored peridium which becomes red on being wounded, the large vesicular cells of the 

 peridium, and the exceedingly strong unpleasant odor. 



This species is nearest the plant treated tentatively as M. rubescens, but careful 

 comparison shows them to be distinct. In section the dried gleba appears much alike 

 in the two plants except that in the Chapel Hill plant the tramal plates are much more 

 distinct. Sections, however, when soaked in water so that they regain approximately 

 the size when fresh show striking differences: in the Blowing Rock plant the "cavities" 

 are invariably stuffed with spores and the tramal plates are thin and rather inconspicu- 

 ous, while in the Chapel Hill plant the cavities are only partially filled, leaving the plates 

 broad and conspicuous. The structure of the tramal plates at maturity is quite 

 different: in the plant from Blowing Rock they are composed of entangled hyphae 

 which are partly gelatinized and which do not break apart easily when crushed; in 

 M. nauseosus they are composed of highly gelatinized hyphae which break apart when 

 crushed into separate units much like the cells in the subhymenial layer in Crucibulum. 

 Furthermore the spores in M. nauseosus are slightly larger and the basidia of the two 

 plants are quite different in shape. 



8281. On and under beech leaves and humus, Nov. 4, 1927. 

 ? Melanogaster rubescens (Vitt.) Tul. 



Plate 109 



During the summer of 1922 we collected in the mountains a single specimen of this 

 interesting plant. Unfortunately no notes were made on the fresh state. Our plant 

 in the dried condition is decidedly shrunken, subglobose, 11 mm. thick; surface dark 

 bay-brown, finely rivulose as if wrinkled in drying and marked on the lower half by a few 

 inconspicuous veins. Peridium simple, 320-450^ thick, composed of irregularly swollen 

 hyphae about 7.4-25/j thick and nearly hyaline under the microscope. Gleba very 

 hard, black and solid, with no cavities; when cut showing a shining surface with faint 

 whitish lines of the tramal plates outlining very large areas up to 1.5 mm. wide, 

 which are not sinuous, but box-shaped like parenchyma cells. These chambers are 

 solidly filled with the hard, black spore-mass, a condition different from species we are 

 referring to Rhizopogon. Tramal plates 35-1 10^ thick. 



Spores smooth, black in mass, light brown under the microscope, subelliptic, 

 3.4-4.2 x 5.5-8.8^, the more mature ones showing the pale cup-like base as in M. 

 variegatus. Basidia short and thick, 7-9 x 12— 15yu, 4-8-spored, the sterigmata short. 



