424 AxxAi.s oi- THK Carnf.gir Musk.u.m. 



Productus gallatinensis ? 



Spirifer grimesi ? 



Spirifer forbesi ? 



Martifiia rosti'ata ? 



Ambocoelia ? sp, 



Seiiiinnla madisonensis var. pctilla. 



Cleiothyris roissyi. 



Piignax cf. inissoiiriciisis. 



Die las HI a turgiduin / 



Loxonema sp. 



Pleiirotoiiiaria sp. 



8. Jack Creek Canon, Montana. 



Caiiiptoiu'ctcs sp. 

 Two other fossils. 



9. Three Fork Shales northwest of Three Forks of the Missouri, 



Montana. 



Spirifer disiiinctiis. 



Cleiothyris n. sp. 

 10. Three Fork Shales. 



Spirifer disfunctiis. 



Cleifltliyris n. sp. 



Camarottvclua tetliys. 



Pi/giiax piig/iiis. 



Go Ilia fifes (2 sp.). 

 "Viewing the collection in the light of present knowledge, 1 be- 

 lieve that two distinct faunas ap]jear in those from the Carboniferous. 

 One is the widely distributed Waverly fauna which characterizes the 

 Madison limestone of the Yellowstone National Park and the lower 

 part of the Wasatch limestone of Utah, and which has now been 

 recognized in almost every western state. The lists i and 2 show 

 this fauna in a very characteristic facies, though crinoids .are much 

 more abundant than they are found elsewhere. With i and 2 should 

 be associated lists 4 and' probably 6 and 7. The other fauna is 

 represented by lists 3 and 5 though the latter is too scanty to be con- 

 clusive. There is little doubt but that this fauna is younger than the 

 other. In my letter to you several years ago I referred it to the 

 Keokuk. At present both because of its faunal characters, though 

 they show certain affinities with Osage types, and its apparent overlap 

 and unconformity with the Waverly beds I am inclined to believe 



