of Burlington, Iowa, and its Vicinity. 



219 



extend the limit of the Devonian rocks, although the lith- 

 ological appearances may not favor such a separation. 

 Thus extended, they will embrace all the beds from No. 1 

 to the lower portion of No. 7, inclusive. The terms " up- 

 per beds " and " lower beds," as here used, refer respectively 

 to the Carboniferous and Devonian rocks as thus defined. 

 The names of fossils in Italics indicate that they are 

 regarded as Devonian, while those in Roman letters show 

 that they are considered as Carboniferous species. 



TABLE SHOWING THE VERTICAL RANGE OF SHELLS. 



Gyrocerns Burlingtonensis, Owen 

 Euomphalus latus, Hall 

 " obtusus, " 

 Spirifer plenus, " 

 " Grimesi, " 

 " extenuatiis, " 

 " subruiundaius, " 

 " biplicatus, " 

 " Forbesi, Norwood and Pratten 

 " solidirostfis, White 

 Nucleospira Bnrrisi, White 

 Aihyris crusskardinalis. White 

 " iiicrassatus, Hall 

 Terebratula BuvUngtonensis, White 

 Rhynchunella Missimriensis'^ Shuinard 

 " ]}ustulosa, White 

 Producius kevico.<lus, White 

 " nrcuaitis, Hall 

 " Fleming!, var. Burling- 

 tonensis, Hall, var. 

 Chonetes Logani, Xorwood and Pratten 



" Ftscheri, 

 * Siroplwmena rugosa, 

 Orthis ineqiudis, 



" Mitclielina, var 



tonensis, 

 " Thiemei, 

 Avicula circulus, 

 Cardiomorpha ovnia, 



Rafinesque 

 Hall 

 Burling- 



Hall, var. 



White 



Shumard 



Hall 



rhoinboidea ? 



* While this paper is in course of preparation, a line from Mr. Wortheu, the 

 Illinois State Geologist, informs me that he also has recognized the shell given ia 

 the table as Slrophomena rugosa, in the Encrinal limestone of Henderson and War- 

 ren counties of his state. The Rev. W. H. P>arris has also placed in my hands 

 some fossils from a locality near Indiantown, Tama Count}', Iowa, among which 

 are recognized Euomphalus latus, Spirifer bipUca(us, Sircplwmena rugosa, Terebrat- 

 ula Burlingtonensis, and an Orthis, all of which are from the same rock there, and 

 are also all found in the Burlington rocks, associated in like manner. 



