HYMENOGASTEACEAE 45 



compact, of closely woven, slender hyphae; gleba warm buff or lighter; cavities globose 

 or polyhedral, half tilled; septa 150-180*1 thick, hyaline, of closely woven slender 

 hyphae, not scissile; basidia hyaline, 7-8 x 5-6^, pyriform, on pedicels about 90/x long, 

 3-spored; sterigmata conical, 2p long; spores hyaline in preserved material, brown in 

 dry material, spherical to ovoid, verrucose to reticulate, leaving a pore where detached 

 rom the sterigma, inclosed in a gelatinous sheath, 8-10ju in diameter. 



"Damp woods. New York. Summer. 



"The peridium of this species appears to be variable in thickness, new cavities 

 seeming to form in the inner layer as the fructification increases in size, with the hyphae 

 next the basidia-bearing hyphae gelatinizing and finally disappearing. A study of 

 young material is very desirable for further interpreting this phenomenon." 



HYMENOGASTER Vitt. 



Subterranean or partly exposed; peridium without superficial veins, not easily 

 removable, in our species white or nearly so; glebal chambers empty at first, sometimes 

 stuffed at maturity; spores oval, lemon-shaped or elliptic, in most cases pointed at the 

 distal end and rough, in some species rounded at the distal end and smooth, but inclosed 

 in a hyaline sac. The spores seem to be the only generic character of any value and 

 they are of two distinct types (if descriptions can be trusted). 



Except for H. anomalus Pk., which Zeller and Dodge have transferred to Lenco- 

 gaster, only one species has been reported from the eastern United States. This was 

 determined by Lloyd as H. decorus, but we are transferring it to H. Thwailesii. We are 

 herewith adding one other. 



Key to the Species 



Odor very strong, not pleasant; spores 6.5-7.4 x 10-13/i, surrounded by a sac H. foctidus 



Odor slight; spores 13-15 x 24-28/1 E, Thwailesii 



Hymenogaster foetidus n. sp. 



Plates 17, 18 and 110 



Plants partly or entirely buried in soil under humus, single or cespitose or often 

 fused, 0.3-1.3 cm. wide by 0.3-0.7 cm. high, when fresh, shrinking to about two-thirds 

 this size on drying, rooting by several basal rhizomorphic strands; subspherical or 

 lobed, fleshy, odor when fresh very strong and persistent, not pleasant, to some sug- 

 gesting aniline oil, to others witch hazel. Peridium 0.5-0.8 mm. thick, simple but 

 often partly covered with white byssoid mycelium, whitish when fresh, changing to 

 creamy buff on drying, not changing color when cut or wounded; tender and fragile 

 when fresh, becoming only slightly toughish on drying; smooth and without ridges or 

 fibrils, but often encrusted with sandy particles, becoming wrinkled on drying ; composed 

 of much entangled, densely packed, thin- and thick-walled threads, the latter often 

 terminating in large spherical swellings 37-55^ thick, which strikingly resemble the 

 oogonia of certain species of Cystopus, except that the swellings are usually empty. 

 Gleba whitish at first, changing'to pale green and then to light brown with a greenish 

 tint, and finally blackish brown on drying; without any signs of a sterile base. Tranial 

 plates arising from the peridial wall and passing inwards in a more or less radial fashion, 

 in some uniting in the center to form a fairly distinct columella. Cavities of the gleba 

 subrotund in the central region, up to 0.6 mm. wide, becoming narrow and radially 

 elongated toward the peripheral region; empty at first, becoming nearly or completely 

 filled with spores. Hymenial layer concolorous with the tramal plates; composed of 



