390 The American Naturalist. [May, 
the smaller tree timbers, which are used in the construction of 
the railings and walks along the Styx and the Dead Sea. These 
are taken into the cave by way of Little Bat Avenue, and Mam- 
moth Dome, being let down from the top, and thence taken by 
Spark’s Avenue to River Hall. Whether this be the real manner 
of spore introduction matters little ; it is important to note that 
a form which almost commonly needs the light and warmth of 
sunshine to develop well here apparently thrives in absolute 
darkness and at a temperature which averages 54°. 
In this same locality occurs the problematical form of basi- 
diomycetous fungus, which is called Rhizomorpha molinaris ?, 
living in the greatest profusion on the old sticks and timbers 
which here abound. Some specimens of beams that have re- 
mained in the lowest and wettest portion of the Mammoth 
Dome for many years are covered from one end to the other 
with the long root-like filaments of this plant. The greater 
number of the living filaments were of a deep brownish color, 
shading into a very light red tip, which became colorless at 
the extreme end. They appeared to be covered with a“ bloom” 
which was lost after touching them. Opportunity to again 
examine them might disclose the phosphorescent phenomena 
for which these forms are celebrated in mines, a fact not known 
to me at the time of their original collection. The species occurs 
in no other part of the cave. 
At numerous localities, where there is some moisture, occur- 
ring on dead specimens of Hadenwcus subterranea, the so-called 
“ cave cricket,” is Isaria (Sporotrichum) densa Link. This fungus 
is one of the most beautiful when growing in suitable stations, 
the mass appearing as a flocculent bunch of cotton clinging 
to the walls or lying on the damp earth. I have found the 
form in many localities, but most abundantly in El Ghor and 
along River Hall. Associated with it is the yellow form to 
which the name of Isaria (Sporotrichum) flavissimum Link has 
been given. But the yellowish form grows less luxuriantly 
and is found on other decaying matter, while the first named 
occurred to me only on dead Hadenwcus. 
A number of moulds and other low forms have been collected 
by me at different times, and been studied by Dr. Thaxter, of 
