1887.] NATURAL SCIENCES OF PHILADELPHIA. 41 



The fossils which have been collected from the strata of this 

 Texas section, have not yet been fully studied with reference to 

 the different formations which they represent. That work has, 

 however, so far progressed as to give some important indications 

 as to the equivalency of certain of these Texas formations with 

 those which different geologists have investigated in the regions 

 to the eastward, westward, and northward from that State; and 

 also to show that a large part of the Texas Cretaceous section is 

 not represented by any of the formations referred to. The 

 following table will serve to formulate these indications, but as 

 the recognition of equivalency is more satisfactory in some cases 

 than in others, each case is considered separately in the following 

 paragraphs : 



Before making comparisons of the Texas section with the 

 others of this table, it is necessary to make some explanations 

 with reference to the relations of the latter to each other. 



The Mississippi section indicated in the foregoing table is that 

 which was published by Prof. E. W. Hilgard in his official report 

 upon the geology of the State of Mississippi.^ The western 

 section is a modification, first proposed by King,^ of the well- 

 known Upper Missouri River section of Meek and Hayden, 

 which is represented by the right-hand column. King, however, 

 placed the equivalents of Nos. 3, 4 and 5 of the Upper Missouri 

 section all together under the name of Fox Hill Group. This 

 being an unnatural grouping of the strata vipon paleontological 

 groimds, I still further modified it by placing Nos. 2 and 3 

 together under King's name of Colorado Group ; and Nos. 4 and 

 5 together under one of the original names of Fox Hills Group 



1 Geology and Agriculture of Mississippi, 1860, p. 3; 



2 U. S. Geol. Expl., 40th Parallel, vol. i, pp. 305, 306. 



3 Ann. Report U. S. Geol. Surv. Terr, for 1876, p. 22. 



