San Juan 

 Basin, N.M. | 





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Piceance Creek 

 Basin.Colo. 



XI ._ 



a. 



M. chomense 



abundant 



(Roan Cliffs Area) 



M. tapiocitis 



abundant 



(S.E.of ColoradoR.) 





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absent 

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absent 



(Red Canyon, 



Almy ) 





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M. cf. robustum 



sparse 

 (Fossil Butte) 



M. cf. robustum 



sparse 



(W.of ElkMt,) 



M.tapiocitis 



(N.W.of Fossil Butte) 





— 

 Green River 

 Basin, Wyo. 



M. chomense 

 abundant 

 (New Fork) 



M. robustum 

 abundant 

 (La Barge) 



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M. cf. robustum 

 (Tipton Butte S 

 Sand Butte) 



M. tapiocitis 

 (near Bitter Creek) 



M.tapiocitis 



(Bitter Creek) 





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Wind River 

 Basin, Wyo. 



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Big Horn 

 Basin, Wyo. 



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4A 

 XI 



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M. semicingulatum 



sparse 



(Cochrane) 





Lost Cabin or 

 equivalent 



Lysite or 

 equivalent 



Gray Bull or 

 equivalent 



Sand Coulee level 



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