Fossils of the Trinity Division. 15 



The Reqniciua. (''Caprolina") Limestone. At Granbury and in 

 southwestern Parker county there is a vast agglomerate com- 

 posed entirely of the shells and casts of Rcquienia texana Room or, 

 to which Dr. B. F. Shumard gave the name "Caprotina lime- 

 stone." This occurs well up in the Glen Rose beds, about one 

 hundred feet from their top. There is a similar bed in the 

 ravine near the east foot of Mount Bonnel, west of Austin. As 

 shown by the writer,* there is another horizon of Caprotina 

 limestone higher in the Comanche Series. 



Th& Ncrinxa Flags. The summit of the Glen Rose beds, as 

 seen in Mount Bonnel, consists of alternations of dimension 

 layers of firm crystalline limestone and pseudo-oolitic marls. 

 Some of these dimension layers in the peak of Mount Bonnel 

 are composed almost exclusively of calcified forms of Nerinteas. 



III. FOSSILS OF THE TRINITY DIVISION. 



The beds contain many plant, vertebrate, and invertebrate 

 remains, which occur either separately or in association, as at 

 one locality in the bed and banks of Paluxy creek, three miles 

 west of Glen Rose, Texas. The more sandy basement beds, or 

 Trinity sands, are, as a rule, deficient in organic remains, with 

 the exception of silicified wood and lignite, although occasional 

 vertebrates and invertebrates are found. 



The lower beds of the Glen Rose subdivision abound in inverte- 

 brate remains, most of which, however, are but badly preserved 

 casts. The Glen Rose beds also contain occasional plants and 

 vertebrates, especially in their lower portion, where they grade 

 into the underlying sands. 



The upper beds of the Glen Rose Division are less abundant 

 in fossil remains, and these are very poorly preserved as casts. 

 The plants of the basement Glen Rose beds have been collected 

 by Professor Lester F. Ward, of the United States Geological 

 Survey, and studied by Professor W. M. Fontaine, of the Uni- 

 versity of Virginia. They are now in course of publication in 

 the Proceedings of the United States National Museum.f The 

 small but interesting collections of vertebrate remains, with the 

 exception of a lepidotoid fish in the hands of Professor Cope, 



* First Annual Report of the Geological Survey of Texas, 1880, Aus- 

 tin, 1890, p. 133. 



fProc. U. S. Nat. Mus., vol. xv, pp. , pis. XXXV-LXIII. 



