BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 VOL. 3, PP 153-172, PLS. 3-5 MARCH 15, 1892 



PRELIMINARY, NOTES ON THE DISCOVERY OF A VERTE- 

 BRATE FAUNA IN SILURIAN (ORDOVICIAN) STRATA. 



BY CHARLES I). WALCOTT. 



( ( )XTEXTS. 



Page 



History of the Discovery 153 



I Ascription of the Locality 155 



The Harding Quarry Section 155 



The Invertebrate Fauna 158 



Harding' Sandstone L58 



Fremont Limestone 159 



Recapitulation 1(>2 



The Vertebrate Fauna 163 



l General Character , 163 



Mode of Occurrence 1 (54 



Position in the geologic Series. ]f>4 



Notes on the ichthyic Remains 165 



Descriptions of the ichthyic Fauna 165 



I >iscussion 168 



History of the Discovery. 



The first discovery known to me of lower Paleozoic fossils in the vicinity 

 of ( Janyon ( 'ity. ( lolorado, was made in 1887 by Mr. S. F. Emmons, of the 

 United States Geological Survey. The collection included two species of 

 la nielli I tranch shells and one species of gasteropod. After examining the 

 specimens. 1 requested Mr. Emmons to have a larger collection made 

 from the same horizon, as the species indicated an unrecognized Paleozoic 

 fauna in Colorado. Mr. T. W. Stanton was employed by Mr. Emmons 

 to collect from the sandstones and limestones above the Ardiean. and a 

 collection was sent in by him accompanied by a sketch of several sections. 

 About the same time Mr. I. C. Russell, of the Geological Survey, while 

 stopping al Canyon City, collected from the lower sandstone a number of 

 specimens of lAngula and several portions of the calcified covering of what 

 is now considered to be the chordal sheath of :i fish. The preliminary 



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