CLASSIFICATION OF THE MISSISSIPPIAN SERIES 309 



The Osage is the best known of any of the Mississippian 

 aunas. Hundreds of species of crinoids founded upon the 

 most perfectly preserved specimens in the world have been 

 described from these strata. Next in importance to the crinoids 

 are the brachiopods, represented by many species. Besides 

 these the corals and bryozoa are often abundant, but the remain- 

 ing classes of organisms are relatively inconspicuous. The fauna 

 has been most studied in Iowa, Illinois, and Missouri, but a 

 good, crinoidal, Osage fauna has been described from south- 

 western New Mexico, 1 and crinoids certainly indicating the 

 presence of the fauna have been described from near Bozeman 

 Mountain. 2 



The Osage fauna has many points of resemblance with the 

 fauna of the mountain limestone of western Europe. In each 

 there is a large crinoidal and a large brachiopod element. 

 Every genus of crinoids in the European fauna is represented in 

 the American, and many species of brachiopods are common to 

 both regions, though the American specimens have sometimes 

 been given different names. The following is a partial list of 

 identical or representative brachiopods in the two regions : 



American species European species 



Athyris incrassatas H. Athyris roissyi L'Eveille. 



A. lamellosa L'Eveille A. lamellosa L'Eveille. 

 Camarophoria subtrigona M. and W. Camarophoria isorhyncha McCoy. 



Chonetes illinoiensis Worthen. Chonetes hardrensis Phill. 



Dielasma hastata Sow. Dielasma hastata Sow. 



Dielasma sacculus Martin. Dielasina saccidus Martin. 



Leptcena rhomboidalis Wilck. Leptana analoga Phill. 

 Orthis{Rhipidomella)burlingtonensis\l. Orthis michelini L'Eveille. 



O. (Sc/zizop/ioria) swallovi H. O. resupinata Martin. 



Productus laevicostus White. Productus cora D'Arb. 



P. punctatus S. Martin. P.punctatus Martin, 



P. burlingtonensis H. P. semireticulatus Martin. 



Rhynchonella plenrodon Phill. Rhynchonella pleurodon Phill. 



Spirifer grimesi H . 

 •S". Logani H. 



Spirifer striatus Martin. 



'A.J. S. (3), XXVII, p. 97- 



2 Bull. 111. State Mus. Nat. Hist., Nos. 10 and 12. 



