QUARTZOSE BOUEDERS FROM CENTERVILLE 
125 
Fig. 2. Nest of brachioipod casts in upper north edge of west boulder. The plate 
is about two-thirds actual size. The component pebbles are distinctly 
shown in this picture. 
(Fig. 2) for the purpose of preservation and more detailed study 
later on. 
From the photograph it will be clearly seen that these Brachio- 
poda are quite similar in outward appearance to some members 
of the Sub-family, Rhynchonellinae Gill. However, it has been im- 
possible for the writer to assign them definitely to any of the 
species described in the literature available for this study. There 
remains also the possibility that we have here a new species, if 
not a new genus which will yet be found far in the northland, 
where little paleontological work has been done, up to this time. 
The Rhynchonellinse group and Brachiopoda of a similar degree 
of development are supposed to occur about midway in the scale 
of brachiopodal life on the planet, and are not listed as occurring 
prior to the Ordovician Period. 
That a conglomerate is younger than its component pebbles 
is a premise which needs no demonstration, therefore either of two 
important facts concerning the correct age of these conglomerates 
must be true. Final determination upon and acceptance of one 
theory precludes the possible correctness of the other : First, 
boulders of this type are not all of Huronian age, as has heretofore 
been supposed by many and, second, if Huronian in age, a highei 
type of life, as evidenced by the fossil Brachiopods of the Center- 
