BARKIS — A DEFENSE OF OUR LOCAL GEOLOGY. 21 



Fifth. Because the testimony of the most distinguished paleontol- 

 ogists of our day is that the difficulty of determining species is so great 

 that errors in identification abound under the most favorable circum- 

 stances. 



This improbability accumulates with each consideration, till we do 

 not hesitate to say that, in our limited exposures of the Corniferous, 

 two hundred and forty-six species never have been, and never will be. 

 realized. In the list occurs the names of fossils that are not found 

 within five hundred miles from Davenport. 



I have thus spoken of the paleontology as set forth in this pamphlet. 

 I pass to a consideration of its geology. 



This pamphlet is as significant in what it leaves out as in what it puts 

 in. On page 19 we read: "No fossils have been published as having 

 been collected in the Corniferous or Upper Helderberg, in either of 

 these counties, in the Iowa or Illinois geological reports." The infer- 

 ence is plain that, since the publication of those reports, no investiga- 

 tions have been carried on in the geology of our locality, except those 

 proclaimed in this pamphlet. 



Some years since the Academy published papers on our local 

 geology, accompanied with illustrations and descriptions of new fossils. 

 We place side by side some of the statements made in those papers 

 and in this pamphlet — the likeness is suggestive: 



Those papers first gave to the quarries below the city the name "Cor- 

 niferous." This pamphlet says, "Corniferous." 



Those papers first divided the rock into two parts — the fossiliferous 

 and the non-fossiliferous. This pamphlet accepts such division. 



Those papers first defined the extent of the fossiliferous portion. 

 This pamphlet recognizes the same boundaries. 



Those papers stated that the Cathedral was built of the non-fossilifer- 

 ous rock found above the city, and Trinity Church of the fossiliferous 

 rock found below the city. This pamphlet says, "Churches and dwell- 

 ings are built of this stone." 



Those papers characterized the rock as most durable. This pam- 

 phlet says, "It shows no signs of disintegration after thirty years ex- 

 posure." 



Those papers first noted the frequent recurrence of large, cavernous 

 openings of greater or less extent. This pamphlet speaks of "numer- 

 ous large pot-holes excavated in the Corniferous limestone." 



Those papers stated that these cavities were filled with sand and 

 shale from the coal-measures. This paper says "filled with arenaceous 

 shales of the coal-measures." 



