Mesozoic and Ccenozotc Geology and P alee ontology. 29 



In 1858, Dr. Geo. G. Sliumard* described the Cretaceous rocks near 

 the mouth of Delaware Creek, on the Rio Pecos, in New Mexico, where 

 be found a thickness of 960 feet. Tlie first 100 feet consists usually of 

 a hard limestone, of a light cream color and earthy texture, and con- 

 tains numerous spheroidal cavities, from a fourth to a half an inch in 

 diameter, which are sometimes partiall}- filled with loose, ferruginous 

 earth. In other places it is softer and lighter colored, resembling im- 

 pure chalk. Beneath this limestone, deposits of gypsum, clay and 

 sandstone occur. In some places the strata are much disturbed, and 

 are found dipping in opposite directions, at angles of 40° or 50°. He 

 also referred to the Cretaceousf certain strata in the bluffs of the Miss- 

 issippi, above Commerce, Missouri, having a thickness of 158 feet, 

 but no fossils were obtained. 



The Cretaceous rocks]; occupy a belt across the State of Alabama, 

 from 50 to 100 miles in width. The counties, either in whole or in 

 part, exposing these rocks on the surface, are Barbour, Russell, Pike, 

 Macon, Montgomery, Butler, Lowndes, Autauga, Wilcox, Dallas, Perry, 

 Marengo, Greene, Choctaw, Sumpter and Pickens. 



T. A. Conrad§ described, from Tippah countj^ Mississippi, Phola- 

 domya tippana, Periploma appUcata, SiUquaria hiplicata^ now Lep- 

 tosolen hiplicatiis, Legumen eUipiicus, L. appressus^ Dosinia densata, 

 Meretrlx tippana, now Aphrodina tippana, Papyridea hella, Car- 

 dium ripleyense, C. spillmani, C. tippanum, Opis bella, 0. hicarinata^ 

 Tellina ripleyana, JSfucula percrassa, Cihota lintea, Cuculloia capax, 

 C. tippana^ now Idonearca tippana, Dreissena tippana. Pinna laq- 

 uata, Gervillia ensiformis, Lima acutilineata, Inoceramus argen- 

 teus, I. costellatus, Ostrea confragosa, 0. peculiaris.^ 0. denticulifera, 

 Uxogyra interriipta, Palvinites argentea, Anomia selloiformis, Sti*om- 

 bus densatus, now Pugnellus densatus, Aporrhais decemlirata, now An- 

 chura decemlirata, Harpago tippanus, now Pterocerella tippana, 

 Pimella curvilirata, Conus canalis, Drillia tippana, D. novemcostata, 

 Turris ripleyana, Fusus novemliratus, F. bellaliratus; Pyrifasus sub- 

 densatus, Ficus octoliratus, Papa supraplicata, Volutilithes cretacea, 

 now Volutomorpha cretacea, Chemnitzia distans^ U. interrupta, Tri- 

 cJiotropis cancellaria^ Tunntella altilis, T. tippana, Lunatia rectila- 

 brum, SoUdulus linteus, Bulliopsis cretacea, Baculites spillmani, B. 

 tippaensis, Scaphites iris, and Cytherina tippana. 



Meek and Hay den || described, from (now the Fox Hills Group) Long 



* Trans. St. Louis Acad. Sci. vol. 1. 



t Proc. Am. Ass. Ad. Hci. % Geo. of Ala., 1858. 



g Jour, Acad. Nat. Sci., 2d ser. vol. 3. Il Proc. Acad. Nat. Sci. 



