202 



W. A. Tarr — Cone-in-Cone. 



and has been so described by others. These rings are 

 composed of clay, usually dark as mentioned above, and 

 are free from carbonates. The ring of clay occupies a 

 depression on the inside of the cone (fig. 8, A and B). 

 This clay is similar to the insoluble residue of the cone- 

 in-cone. The rings are broadest and most numerous in 

 the more impure specimens of cone-in-cone. The ridges 

 between the rings are striated and have the same slope 

 as the outer surface of the cone, fitting into the cone-cup. 



Fig. 5. 



Fig. 6. 



come sea 



Fig. 5. — Conic scales on the side of cone. 



Fig. 6. — Basal outline of a cone, with conic scales on the sides. 



Fig. 7. 



Fig. 7. — Rings in cone-in -cone. 



The cones may be oblique especially near the edge of 

 a cone layer. Some may have the apex removed and 

 others may be more or less bent and twisted. A peculiar 

 feature of the cones in layers, not associated with con- 

 cretions, is the flaring of the base and the acute apex 

 (see fig. 9) . Such cones are common in Bond Co., Illinois, 



