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234 Some facts brought to light by deep wells in Des Moines 
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238 Laccolites in southeastern Colorado. 
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239 The origin of hypotheses, illustrated by the discussion of a 
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240 [Review of "Elements of geology, a text-book for colleges and 
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241 Age of the Potomac formation. 
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242 Gill (Thomas). Note on the Devonian Paheospondylus. 
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Quotes Dr. Traquair's description of Pakeospondylus gunni and dis- 
cusses briefly their relations. 
