30 The American Geologist. January, i904. 
It may be well here to quote from professor J. W. 
Dawson, who, speaking of waste macrospores, or larger spores 
of a species of cryptogamotis plant being dispersed in countless 
millions of tons through shales of the Devonian of Canada, 
and the United States, refers these to rhizocarps. The walls 
or enclosing sacs of these macrospores, professor Dawson con- 
siders to have been of very dense consistency, appearing now 
as a highly bituminous substance agreeing with those of the 
spores of lycopods, and like them having been of a highly car- 
bonaceous and hydrogenous quality, very combustible and 
readily admitting of change into bituminous matter ; from 
this composition it is readily concluded that such spores are 
admirably suited for the production of highly carbonaceous or 
bituminous coal. The remarkable uniformity of structure and 
form of those bodies over great areas, combined with the great 
thickness of the rocks containing them, and the absence of any 
other kind of spore case make a striking coincidence. The 
true sporangites are round and smooth with thick bituminous 
walls which are punctured with minute transverse pores. The 
black shale of Ohio and similar shales of the same geological 
age (Devonian) in Brazil also abound in like organisms. Sim- 
ilar forms also occur in the white coal of Australia and Tas- 
mania. 
BitiDiiinoiis Rocks in Missouri. 
Bitumen occurs in western Missouri from Caldwell county 
on the north to Newton county, a distance of 175 miles north 
and south, and a width of from 25 to 40 miles east and w^est. 
It has been found in ten counties of Missouri, the rocks ap- 
parently becoming more bituminous in their southern exten- 
sion. From Cass county southwardly, and extending into 
Kansas, tar springs are of frequent occurrence. Although the 
rocks often appear black and oily drops are seen oozing out, 
and pools of tar are formed, still the amount does not seem to 
be concentrated in quantity sufficient to pa)- for the working. 
Its mere presence has occasioned the sinking of several deep 
wells with no profitable result. There are no positive anticlin- 
als nor synclinals in this district. Its greatest vertical extent 
is 600 feet and averages 300. lying chiefly in the lower Coal 
Measures although it is found in sandstone just below the 
upper Coal Measures. It is also found in the Lower Carbon- 
