EEVISION OF ENDOGONEAE. 299 



Endogone Ludwigii Bucholtz (1911), p. 194, Taf. IX, figs. 77-87. 

 E. sphagnophila Atkinson (1918), p. 16. 



E. xylogena Schroeter (1887), p. 260, nee. Saccardo (1877), p. 14, sub Proto- 

 myces. Thaxter (1897), p. 12. 



Spore-masses waxy when fresh, horny when dry, pale to golden 

 yellow, becoming- somewhat orange yellow, subspherical to reniform, 

 or lobed, less often convolute, flattened, umbilicate below: covered by 

 a thin tomentum, clear white when dry, formed by characteristic, 

 thick-walled hyphae 4-6 m in diameter with numerous free, projecting, 

 distally attenuated branches. The substance of the spore mass con- 

 sisting of an irregular plexus of stout branching non-septate filaments, 

 showing numerous irregular vesicular enlargements, becoming more 

 or less ol:)literated as the irregularly crowded, broadly ellipsoid to 

 ovoid, thick-walled, pale orange yellow zygospores mature. Spore- 

 masses (dry) 2-7 X 1-2 mm. thick. Zygospores, 35-GO X 30-45 ju, 

 the wall subhyaline 3-5.5 n thick. Peridial hyphae X 3-8 /x. 



Usually above, rarely below the leaf cover; on mosses, especially 

 near the tip of Sphagnum; on leaves, twigs, dung, rotten logS; etc., in 

 moist situations, especially in coniferous woods. Temperate Europe 

 and North America. 



This species is without doubt very generally distributed in temper- 

 ate America; since it is already known to occur in Maine, New Hamp- 

 shire, Connecticut and eastern Tennessee (Thaxter); West Virginia 

 (Sturgis); New York and Maryland (Atkinson), and in Michigan 

 (Kauffman). In my own experience it has proved not at all uncom- 

 mon, and was first met with at Kittery Point, Maine, in 1886, when 

 young conditions, showing the early stages of conjugation were ob- 

 tained. Although it is found most frequently at or near the tips of 

 Sphagnum, especially in moist coniferous woods, and is conspicuous 

 in this position from its bright color, it bears no definite relation to 

 this substratum as a host; since it occurs also, as above indicated, on 

 various other substances. Its waxy consistency, when fresh is, as 

 noted by Schroeter, characteristic; as is the hard almost horny char- 

 acter of the dry spore mass, which loses its bright color, becoming 

 dirty yellowish; the variably developed superficial tomentum assum- 

 ing a more noticeable clear white appearance, owing probably to the 

 refractive character of the thick walled filaments which compose it. 

 The size and form of the spore-mass varies considerably from nearly 

 round to flattened and somewhat convolute. The largest individual 

 seen measures 7 mm. in width when dry. 



The early conditions of development are much more difficult to 



