THE RECURRENCE OF TROPIDOLEPTUS CARINATUS 

 IN THE CHEMUNG FAUNA OF VIRGINIA 1 



E. M. KINDLE 



U.S. Geological Survey 



For many years after the standard sections of the New York 

 Devonian formations and their faunas had become well known, 

 the brachiopod Tropidoleptus carinatus was supposed to be con- 

 fined in its geologic range to the 1,100 or 1,200 feet of shale com- 

 prising the Hamilton formation in central New York. No trace 

 of this fossil has ever been found in the typical Genesee and Portage 

 faunas which follow the Hamilton fauna in west central New 

 York. The entire absence of the species from the Genesee and 

 western Portage faunas of New York seemed to indicate that the 

 life of the species came to an end with the close of Hamilton sedi- 

 mentation in central New York. But the discovery of T. carina- 

 tus in the Chemung of southern New York 2,000 feet above the 

 top of the Hamilton by Professor H. S. Williams 2 several years ago 

 proved that this species instead of becoming extinct at the close 

 of the Hamilton had only changed its habitat. More recently 

 Williams and Kindle 3 have found that Tropidoleptus carinatus 

 and other well-known Hamilton species comprise the major part 

 of the fauna at certain Chemung horizons in southern New York 

 2,000 feet or more above the top of the Hamilton formation. In 

 this paper it will be shown that this and other Hamilton species 

 reappear in the Chemung fauna of Virginia as they do in New 

 York. The appearance of T. carinatus in the Chemung fauna of 

 Virginia in abundance is especially notable because it is seldom 

 found at the horizon of the Hamilton fauna so far to the southwest 

 in this part of the Allegheny region as the occurrence in the rocks 

 of Chemung time which will be described. 



1 Published by permission of the Director of the U.S. Geological Survey. 



2 Bull. U.S. Geol. Survey No. 3 (1884), 24. 



3 Amer. Jour. Science, XIII (1902), 427-30; Bull. U.S. Geol. Survey No. 210 

 (1903), 90-91. 



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