138 Vil BCI INAVEIO) Val, JOVAIE YZ 
under the lower, and show clearly the effect of deformation 
along the radii of the equator. In fact, the impression is at 
once given the observer that centrifugal force of nearly equal 
amount has been exerted along all radii of each sphere (Figs. 2, 
3,and 5). A similar disturbance of the usual, nearly horizontal, 
attitude of the beds of this formation has been noted by New- 
Fic. 3. Deformation of the shale about a medium-sized concretion. 
berry at Worthington, Franklin county, Ohio, and by Rominger 
in the “Black Shale” of Michigan.’ 
The concretions themselves are composed essentially of 
crystallized carbonate of lime, the crystals arranged radially and 
always in direct contact with one another. There is practically 
no argillaceous material in them, and in no observed case does 
the stratification of the country-rock run through the concretion, 
The shape is usually that of the almost perfect sphere (Fig. 4), 
though often this form is somewhat lost by the slight flattening 
t Geology of Ohio, Vol. I, 1873, p. 155. 
2Op. cit., p. 66. 
