LIFE 



437 



Kvline. The most distinctive feature was the commingling of the 

 (irvut Hasin and the Osage faunas. It introduced into the main 

 Miissi|>i>iun sea what seemed to be a retrograde change, for 

 spirits of Devonian aspect that still lived in the isolated Great 



Jasin province and elsewhere, migrated eastward, and their relics 

 irv found with species whose evolution had reached an advanced 



[ississippian phase. 

 Crinoids were less plentiful than in the Osage fauna, and notably 



langed (Fig. 380). Of one group which had upwards of 300 species 

 in the Osage fauna, less than 25 species are known in the later faunas, 

 and among the 25, no Osage species is found. Other groups of 



sw 



t 



Fig. 381. CHARACTERISTIC UPPER MISSISSIPPI ANT FOSSILS: a, Endothyra 

 bailey! Hull, ;i small foraminifer, much enlarged, abundant in the Bedford limestone 

 of Indiana, and often mistaken, in the past, for an oolitic concretion; b, Archimnics 

 awallovanns (Hall), a bryozoan having a peculiar screw-like axis for the support of 

 ".e colony., c-h, brachiopods: c, Xpirifirina spinosa (N. and P.), a genus which 

 veloped from Spirifer, and has its greatest development in the late Mississippian 

 and Pennsylvanian; d, Seminula subqmulnita (Hall), a species closely related to 

 Pennsylvanian types; e, Spirifer increbescens Hall, a species characteristic of the 

 later Genevieve faunas;/, Eumctria ntarcyi (Shum.), a representative of a genus 

 abundant in the Genevieve faunas. It was present in the Kinderhook, but has not 

 n found between the Kinderhook and the closing stages of the Osage; g, Prodiic- 

 fasciculaius McCh.; h, P. marginicinctns Prout; i and j, pclecypods: i,Schizo- 

 chfslcrensis M. and W.; j, Conocardium pnitlcinnnim Hall; k-m, gastropods: 

 , Bcllerophon sublavis Hall; /, I'ltitrotonnirin noduloslritita Hall; m, Eotrociis con- 

 vus Hall, n and o, cephalopods: n, Orthoceras annulaio-costahtm M. and W., 

 me of the ancient type of straight cephalopods, occasional species of which per- 

 'sted to the end of the Paleozoic; o, Goniatitcs k< ntnck ii-nsis S. A. M. 



