322 THAXTER. 



A comparison of these four gatherings indicates that, although the 

 spores of the Magellan specimen are distinctly larger, the other three 

 are not separable, and correspond in all essentials. Bresadola, in his 

 description, speaks of monosporic asci in which the spore is clearly 

 distinguished, but was probably misled by the appearance of young 

 sporangia in which the contents was still continuous, not having yet 

 divided into spores. 



The sporangiocarps of this species which occur on or just under the 

 leaf cover, are subspherical to reniform, umbilicate, yellowish when 

 dry, nearly white when fresh, 4-10 mm. in diameter, sometimes 20 mm. 

 according to Spegazzini, and arise from a ropy mycelium which may 

 form a more or less distinct stalk as in E. viaUeola. In the specimens 

 examined there is no peridial layer distinguishable, the surface being 

 composed of sporangia and slightly projecting scanty hyphal elements. 

 The fertile hyphae are sparingly septate and branched, bearing the 

 sporangia terminally and diverging from a cushion-like basal region 

 associated with the umbilicus. The sporangia are more commonly 

 spherical, but, as in E. malleola may show variations in length and 

 breadth and may be asymmetrical in outline (Figs. 01-62). At 

 maturity the sporangium wall collapses about the spores and follows 

 their irregular contour. The average diameter is about 35-40 ^, but 

 may reach 60 ju or over. The spores, which are evidently formed by 

 cleavage of the whole contents in these sporangia, vary in number from 

 four to a dozen or even more, although Spegazzini mentions eight, 

 only, and are rather variable in size and irregular in shape from mutual 

 pressure. In the Brazilian and Argentine material, Figures 64-71, 

 they, are 12-30 X 12-25 ix the average about 18 X 20 n, but in the 

 Magellan material, Figures 60-63, they are for the most part distinctly 

 larger, 20-38 X 14-34 yu. The number present in a single sporangium 

 varies from four to a dozen or more; although, as stated by Spegazzini, 

 there are often not more than eight. This number is, however, by no 

 means constant or even characteristic. On the rupture of the spor- 

 angium wall they are readily set free, although when fully mature, 

 Figures 67-68, they appear to be held by the collapsed sporangial 

 wall and rather firmly coherent. They are quite hyaline and con- 

 tain, as a rule, one or more large oil globules or coarse dense granules. 



A second Argentine collection from La Plata sent me by Spegazzini 

 doubtfully determined as this species, proves to be E. fulva, as already 

 mentioned. 



