HARRIS — A DEFENSE OF Ol'R LOCAL GEOLOGY. 19 



Cyathophyllum and Zaphrentis, Professor Rominger has noted and illus- 

 trated nine species, and Professor Winchell about six, making a sum 

 total of fifteen. This pamphlet credits our limited locality with thirty- 

 three — more than twice as many as are found in the whole State of 

 Michigan. 



I pause for a moment over another feature of this pamphlet. It is 

 admitted that certain fossils not only have a wide range, but reappear 

 in successive formations. But it is an unheard of phenomenon, until 

 this pamphlet broached it, that, in any locality circumscribed as ours, 

 out of two hundred and forty-six species, one hundred and fifty-nine 

 are characteristic of the Corniferous limestone, and eighty-seven are 

 representatives of other and distant rocks. It reaches the proportion of 

 almost two-thirds of the whole number reported as found. Call the roll, 

 and Trenton responds, 1; Clinton, 3; Niagara, 14; Guelph, 1; Lower 

 Helderberg, 5 ; Onondaga, 3; Schoharie Grit, 7 ; Oriskany, 3; Cornifer- 

 ous, 159; Hamilton, 35; Tully, 2; Chemung, 2; Burlington, 1; Up- 

 per Helderberg, 2 ; Marcellus Shale, 2 ; 28 so unfortunate as to be un- 

 named.* 



That such a heterogeneous assemblage should mass itself within the 

 compass of our few quarries is an anomaly having no parallel within 

 the range of geological investigation. 



The identification of fossils is a work of acknowledged difficulty, 

 even with the best of facilities. In proportion as there is a deficiency 

 in authorities and means of comparison, especially if the fossils are in a 

 poor state of preservation, the difficulty is greatly enhanced. Illustra- 

 tions of this difficulty abound. One can scarce go amiss for them. 



Professor White, of the Smithsonian Institution, gives two figures 

 of a certain coral so common that ninety-nine out of a hundred col- 

 lectors would not hesitate to name it. He declines either to de- 

 scribe or identify it, on the ground of the necessity of a thorough 

 revision of the fossil corals of our country, and the consequent doubt 

 that is naturally felt as to the correctness of specific determinations by 

 means of merely the external features. External characteristics, it is 

 true, will always remain valuable aids in the specific determination of 

 fossil corals; but in the present state of paleontological science one is 

 not justified in omitting microscopic and other details of internal 

 structure. 



Professor Worthen, of the State Geological Survey of Illinois, thus 

 writes of a certain spirifer: "This shell seems closely allied to several 



♦Pamphlet, p. 19. 



