244 STRATIGRAPHIC CATALOGUE. 



With the many natural difficulties to be taken into con- 

 sideration, it is readily understood that from a geological or 

 biological point of view, any stratigraphic tabulation of the 

 fossils of the state must necessarily be quite incomplete for 

 years to come, and must long lack uniformity in the number 

 and kind of organisms assigned to each horizon. Neverthe- 

 less, in the present condition there is a peculiar economic im- 

 portance in a special arrangement of the forms known at the 

 present time to occur within the limits of Missouri or on its 

 borders, according to the strata in which they are found. 

 With the general geographical distribution known by reference 

 to the colored geological map, the fossils which may be ex- 

 pected to be found in any locality in the state may be quickly 

 referred to without the labor of going through the whole report 

 to pick them out. The fossils forming as they do labels to the 

 deposits of commercial value, put a ready and inexpensive 

 means in the hands of even the most inexperienced for deter- 

 mining what minerals of economic worth are to be sought for 

 in the particular neighborhood, and what are not to be expected. 



