Jan. 1905] 
A New Species of Sphaerosoma 
3 
2 to 2.5 mic. broad at the base, often bent at their apices, at matu¬ 
rity extending to the outer surface of the exospore; spore, exclud- 
inging exospore 25 mic. in diameter, including spines or exospore, 
35 mic. in diameter; paraphyses large, clavate, septate, brownish, 
12 to 15 mic. in diameter at the apex; sterile part of the receptacle 
composed of rather loosely interwoven hyphse, grading into 
pseudo-parenchyma, cells large. 
Habitat—On the surface of damp soil between the tufts of 
grass in an open place, in the margins of woods near Iowa City. 
Plants collected from June to October. 
The specific name under which these plants are described is 
suggested by the character of the markings of the spores, which 
are distinctly echinulate. 
The description and measurements given above were made 
from fresh material collected at different times. Specimens pre¬ 
served in alcohol vary somewhat; the most of the color disap¬ 
pears and the plants are a little contracted and the measurements 
are therefore a little less. 
The plants described above were collected during the later 
part of the month of June in the summer of 1904, in large num¬ 
bers in a ravine near Iowa City and upon examination were at 
once referred to this genus. The individuals are at first almost 
spherical in form, smooth on the outer surface, and of a whitish 
or lead color. As they mature, a small, brown spot is formed in 
the center of the supper surface, the brown color gradually 
spreading until it covers all of the exposed surface. They are 
at first regular in outline, becoming, at maturity, irregularly con¬ 
volute and more or less depressed, so that at maturity the plants 
are roundish but more or less irregular in form, of a deep brown 
color and with a soft velvety appearance. Examination of sec¬ 
tions of young plants shows the brown spot on the upper surface 
to be the beginning of the development of the hymenial layer and 
the brown color and velvety appearance to be due to the large 
paraphyses which contain brown coloring matter. 
During the early stages of their development, the spores are 
located near the end of the ascus; they then spread out and 
become alternately arranged as shown in the diagram and at last 
are disposed in one row. They are at first smooth and filled with 
numerous oil drops which disappear as the spore matures and the 
whole body of the spore is surrounded by a transparent exospore. 
The first appearance of the roughenings on the outer surface 
occurs at the periphery of the spore proper within the exospore, 
the thickenings being at first very slight but gradually increasing 
until they reach the outer surface of the exospore. When mature 
a faint line may often be seen near the tips of the spines which 
is the boundary of the exospore but these become indistinct and 
in alcoholic specimens and often in mature spores of fresh mate¬ 
rial the boundary of the exospore is not visible at all, although at 
