294 H. T. Hill — Texas Section of American Cretaceous. 



The strata of the upper half become thinner and thinner and 

 the fauna assumes a more littoral aspect toward the top, as in 

 the Ripley beds of Tippah Co., Miss., the Navarro beds of 

 Texas and the Fox Hills of Meek and Hayden. Along the 

 lower Rio Grande the strata meet, and are either covered by or 

 become identical with other strata having the lithologic and 

 faunal characteristics of Meek and Hayden's No. 4 and 5, and 

 which are the direct geographic continuation along the face of 

 the Rocky Mountain axes of the same formation as exposed in 

 New Mexico and Colorado. 



Concerning this and all the following groups it is but proper 

 to remark that the paleontology of Texas is of an unsatisfac- 

 tory nature, and that hone of it has been done or revised in 

 accordance with modern biologic methods. Dr. Roemer's 

 paleontologic descriptions are models of descriptive excellence, 

 and it is easy to trace whatever element of error may occur in 

 them, but the writings of most other writers have been 

 fragmentary and unsatisfactory, being unaccompanied by any 

 definite horizon or locality. Many of the fossils from Texas 

 described by men who have never visited the State, convey no 

 idea of their geological horizon, and several of the most com- 

 mon forms have been confusingly re-described. Most of the 

 names given were in the days when species-making was looked 

 upon as the chief accomplishment of the paleontologists, and 

 resemblances were oftentimes intentionally ignored in order to 

 add new names to the category. It was in this manner that 

 many of the fossils from Texas have been twice, sometimes 

 thrice, described under different names by separate authors. 

 The latest descriptions of Texas Cretaceous fossils describes 

 three alleged new genera, one of which had been described 

 over a year ago under another name.* 



With the assistance of the author's description, verified by 

 years of personal investigation, I have recognized the following 

 fossilsf belonging to this upper grand division of the Creta- 

 ceous in Texas. 



Nodosaria texana Con. 



Terebratula guadalupce Roem. 



TZemiaster ( Cassididus) para- 

 status Mort., Desor. 



Hemiaster texanus Roem. 



Exogyra costata Say. 



Exogyra costata,vea\ ponderosa 

 Roem. 



Exogyra fragosa Con. 

 Exogyra Imviuscula Roem. 

 Exogyra subspatidata Roem. 



Con. 

 Gryphma aucetta R,oem. 

 Ostrea Lyonsii Shum. 

 Ostrea Owenana Shum. 

 Ostrea planatovata Shum. 



* See Proc. Philad. Acad. Nat. Sci., Feb., 1887. 



f These lists are not the result of guess-work, but of the most careful strati- 

 graphic observations and compilation. It has been my endeavor for years to 

 learn the exact stratigraphic horizon and range of the numerous fossils described 

 from Texas, few of which were accompanied by any stratigraphic data. 



