REPORT OF THE STATE GEOLOGIST. XXIX 



In the Cretaceous a clear and comprehensive section of the system 

 as it appears in the area has been obtained, which not only develops 

 facts of some scientific importance, such as the absence of the Alter- 

 nating Beds of the Fredericksburg Division, but furnishes economic 

 results also that will in time be of considerable interest to that portion 

 of the State. 



PALEONTOLOGY. 



The necessity for a correct knowledge of the fossils occurring in the 

 different formations, and even in the different beds of the same forma- 

 tion, is as absolute for the correct determination of certain economic re- 

 lations as any other branch in the science of geology. 



The fossils are the guide boards of the geologist, and in spite of the 

 fact that in many cases practical men look upon the labors of those 

 whose time is given to such study as an utter waste, they must be 

 studied in order that the exact succession of the rocks be known and 

 their relations accurately defined. This is easily understood and ap- 

 preciated if we take into consideration that each separate series of rocks 

 has its own characteristic fossils, and that having definitely determined 

 these, and by them the relations of the underlying and overlying strata, 

 we can make a section showing the succession and thickness of each 

 series of beds, and from such section in many cases tell exactly the 

 chances for artesian water, for coal, or oil, or natural gas, and many other 

 substances, at any point at which any one of the beds so determined 

 may appear upon the surface, and often very closely approximating the 

 depth at which they lie. In the Coal Measures, for instance, there is a 

 persistent band of limestone with a certain association of fossil forms. 

 We have determined them and know from observation that a coal seam 

 lies a certain distance below them. Therefore at any place at which this 

 limestone appears upon the surface, or where we find its characteristic 

 fossils, we immediately begin the search for the coal seam. Many other 

 instances of equal importance might be given of the economic use of 

 the study of fossil forms. Of its relations to knowledge from the 

 standpoints of biology and world-building it is unnecessary to speak. 



While this is true, we have found it almost impossible to do anything 

 in this direction here owing to a lack of books and type specimens for 

 reference. We have therefore taken advantage of the kind offers of 

 assistance that have been made at different times, and have by this 



