4 INTRODUCTION. 



No. 5. Soft white limestone, with Nautilus Dekayi, Baculites ovatus, Scaphites Conradi, Gryphaea 

 vesicularis, Exogyra costala, etc. ; 6 feet. 

 Dark limestone, with obscure casts of shells ; 4 feet. 



In Texas the formations consist mainly of compact limestone. Dr. Shumard^ gives 

 the following section : — 



Earlier Cretaceous — 

 No. 1. Marly clay, with Ammonites Swallovii, A. Meehianus, Ancyloceras annulatus, Scaphites 

 vermiculus, Baculites gracilis, Inoceramus capulus, etc. ; 150 feet in thickness. 

 Arenaceous beds, with Ostreo/ hellarugosa, remains of fishes, etc. ; 80 feet. 

 No. 2. Caprotina limestone, with Orbitolina Texana, etc. ; 55 feet. 



Blue marl, with Inoceramus problematicus, etc. ; 50 feet. 

 No. 3. Washita limestone, with Gryphsea Pitcheri, Inoceramus problematicus, Eamites Fremonti, 

 etc. ; 100 to 120 feet. 

 Indurated blue marl, with Exogyra arietina, etc. ; 60 feet. 



Later Cretaceous — 

 No. 4. Austin limestone, with Gryphaea vesicularis, Exogyra costata, Nautilus Dekayi, Baculites 



anceps, remains of fishes, etc.; 100 to 120 feet. 

 Comanche Peak Group, with ^Exo^yra Texana, Grypjhsea Pitcheri, Cardium mult islri alum. 



Ammonites Pedernalis, Heteraster Texanus, Diadema Texana, etc. ; 300 to 400 feet. 

 Caprina limestone, with undetermined species of shells; 60 feet. 



Other localities^ of Cretaceous formations of the different subdivisions are as 

 follows : — 



No. 1. At difi'erent points in New Mexico. (Newberry.) 



No. 2. On the north branch of the Saskatchewan, west of Fort k la Corne, lat. 54° N., in New 



Mexico: (Meek.) 

 No. 3. Over the region from Kansas through Arkansas to Texas ; Pyramid Mountain, N. Mexico. 

 No. 4. In British America, on the Saskatchewan and Assiniboine ; on Vancouver Island ; Sucia 



Islands, iu the Gulf of Georgia. 

 No. 5. At Deer Creek, on the North Platte, and not identified south of this. (Meek and Hayden.) 



' Transac. Acad, of Sciences of St. Louis, I, 583. 

 " Dana, Manual of Geology, 470. 



