Murrill: Illustrations of Fungi 
289 
often aculeate behind with age ; context white, coriaceous, 1-5 mm. 
thick ; tubes soon splitting into teeth, which are 1-2 cm. long, 
compressed to subulate, slender, more or less pointed, dentate or 
incised, puberulent to glabrous, white to pale-flesh-colored, about 
I mm. apart at the base ; spores globose, smooth, hyaline, 5-7 (i. 
This species occurs rather sparingly on dead deciduous wood in 
temperate North America. It is interesting because of its close 
resemblance to the Hydnaceae. The specimens figured were col- 
lected on the Garden grounds in August, 1911, growing on the 
dead top of a red maple fifty feet above the ground. 
Poronidulus conchifer (Schw.) Murrill 
Shell-Bearing Polypore 
Plate 105. Upper Figure 
Pileus thin, coriaceous, dimidiate to flabelliform, usually nar- 
rowly attached, conchate, springing from a sterile, cup-like struc- 
ture, which usually appears on the mature sporophore near the 
base, 1.5-2 X 2-4 X o. 1-0.2 cm. ; surface white to isabelline, with 
pale-latericeous zones, finely tomentose to glabrous, the sterile 
portion avellaneous, with narrow, black, concentric lines ; margin 
thin, concolorous, undulate ; context very thin, membranous, 
white, less than i mm. in thickness ; tubes short, about i mm. 
long, thin-walled, white, mouths angular, irregular, 3 to a mm., 
edges thin, uneven, dentate ; spores ellipsoid, smooth, hyaline. 
Very common on fallen branches and dead limbs of elm through- 
out eastern North America as far west as Kansas. The genus is 
monotypic and is peculiar in having the fertile portion of the fruit- 
body develop from a sterile, cup-like growth, which is often found 
on the back of the mature pileus. 
Scutiger griseus (Peck) Murrill 
Gray Scutiger 
Plate 105. Lower Figure 
Pileus circular, often irregular, convex, 7-12 cm. broad, i cm. 
or less thick ; surface glabrous or minutely tomentose, cinereous, 
slightly darker toward the center ; margin thin, concolorous, often 
