610 



GEOLOGY 



probable that the explanation of their paucity lies in organic condi- 

 tions or relations, perhaps in the corals themselves, perhaps in 

 unrecorded enemies, or perhaps in the preoccupation and rivalry 

 of the crinoids. Brachiopods (Fig. 431), as usual, held a leading 

 place in the fauna, and some of their species ranged to the eastern 



Fig. 431. Osage Fossils: a, Zaphrentis centralis E. and H., the most 

 characteristic coral of the Osage. b-i, brachiopods: b, Spirifer suborbi- 

 cularis Hall; a closely allied species occurs in Europe, c, Athyris lamel- 

 losa L'Eveille, a species common to America and Europe; <l, X/;/Y//rr 

 logani Hall, the American representative of Spirifer striatus of the Euro- 

 pean Mountain limestone; e, Productus burlingtonensis Hall, a species 

 abundant in the Lower Osage; /, Leptcena rhomboidalis Wilck, a 



which persisted from the Ordovician to the Osage; g, Rhi/>n/<n<'/!<i 

 burlingtonensis (Hall); h, Reticularia pseudolineata (Hall), a spiiv-l>r:ir- 

 ing hrachiopod having a closely allied species in the European Mountain 

 limestone; i, Schizophoria swallovi Hall, one of the last represent at ivi-s 

 of the orthids. 



continents. Mollusks were subordinate, a few winded /W< </// W.v, 

 a few capulid gastropods, an occasional pteropod, and an even rarer 

 cephalopod, making up the poor representation of this class. There 

 were a few lingering trilobitcs and some other crustaceans, an 

 ample growth of bryozoans, some supposed sponges and doubtless 

 many forms not readily fossilized. Marine plants left but an 

 obscure record. 



