366 The American Geologist. June, isos 
laria arrested my attention at once. Parts of carbonized bark are 
still attached to the Sigillaria and between the mycelia of the fun- 
gus thin layers of coal are observable, showing that an effort was 
made b3'the resinous bark to exclude the intruder in coating it with 
its substance, until the fungus prevailed, separating the bark from 
the decaying substratum, and in falling was buried in a calcareous 
sea; hence the impossibility of preservation of its cellular arrange- 
ment or filamentous texture. The fine calcareous mud has filled 
its soft and loose tissue, calcifying it thoroughly, leaving only its 
unmistakable form and habitat. The Sigillaria, retaining some of 
its carbonaceous matter with faint traces of cicatrices, is thinl}'^ 
covered with fine fragmentary crinoids and shells, as is also its 
parasite. The limestone slab, bearing on its surface these forms, 
contains the common fossils of that time. 
The substance of the fungus above described is of dirty yellowish 
color and of chalk}' softness, quite difl'erent from the hard, dark- 
bluish limestone. It is without an}- carbonaceous matter, fuUj'' 
concurring with another most remarkable fungus of a quite differ- 
ent genus from coal No. 5, Tuscarawas Co., 0., the substance of 
which is essentially the same. The latter is a most remarkable 
preservation with cellular arrangement and sporiferous tubes, and 
is astounding in size and generic character. It will be described 
in another paper. 
RECENT CHANGES IN THE MUIR GLACIER. 
By S. Prentiss Baldwin, Cleveland, Ohio. 
A comparison of the measurements of motion of the Muir gla- 
cier made by Prof. G. F. Wright, in 1886, with those made by 
Prof. H. F. Reid, in 1890, brings out strongly the dependence of 
a o-lacier upon the minor and perhaps local changes of climate, and 
the rapidity with which the effects appear. 
In 1886 Prof. Wright reported a rate of sixtj^-five to seventy 
feet a day in the most rapidly moving portions;* but in 1890 Prof, 
Reid found no higher rate than a little over seven feet a day.f 
The bare statement of this apparent discrepancy, without 
any explanation, ver}- naturally led, at first, to the belief 
that one set of measurements must be incorrect, and as 
*Am. Jour. Sci., Jan., 1887; Ice Age in North America, 1889, p. 50. 
fNational Geographic Magazine, vol. iv, p. 44. 
