524 TRANS. OF THE ACAD. OP SCIENCE. 



occupy a position so disagreeable, and as these men expect 

 all geologists to accept their views and rely upon their tacts, 

 I would suggest to Messrs. Meek and Hayden to review all 

 their papers on Western Geology and Palaeontology, and so 

 arrange the facts and theories therein expressed that we may 

 know what their views really are at the present time, espe- 

 cially on those points about which they have so many times 

 changed. Will they, as guardians of our Western Geology, 

 tell us, once for all, whether there really is any Permian Sys- 

 tem in the West? Whether the genus Bellerophon is ever 

 found in Permian Rocks ? Whether the genera Monotis and 

 Bakevellia are any proof of this system ? 



Do they now think, as in 1859 * that the Triassic of my 

 section " may be Jurassic, or Triassic, or both, though * * ! 

 we rather incline to the opinion that they may prove to be- 

 long to the former?" Or do they still think, as in July, 1867,t 

 that "they may be Triassic, Permian, or even Jurassic, 

 * * * we are much inclined to believe they will be found 

 to belong to the Trias" ? 



Will they tell us how it happens that they found Belle- 

 rophons in No. 10, the PermianJ of the Kansas Section, and 

 in E. the Permian§ of their Nebraska Section, when they 

 believe this genus "to be either exclusively Carboniferous, 

 or not found above the Coal Measures."|| 



There are in the various papers of our authors scores of 

 statements which appear to me equally inconsistent with 

 scores of other statements in the same and other papers, and 

 it is due to themselves and science that these invaluable 

 papers be revised, and these blemishes be removed. 



Our authors have made so many changes in the nomen- 

 clature of our fossils that Prof. Geinitz and myself have not 

 always used the last name, and they, while reviewing our 

 works, have much trouble in correcting us, and telling their 

 readers what fossils we wish to designate. This makes them 

 appear a little pedantic, and could be avoided if they would 

 only tell us what names they intend finally to adopt. 



To illustrate how difficult it is to keep up with their 

 changes of nomenclature, the short history of one fossil will 

 suffice. The Encrinus moniliformis of Marcou, Messrs. Meek 

 and Worthen changed to the genus Erisocrinus in March, 

 1865, then to Philocrinus in May of the same year, and back 

 to Erisocrinus in August following. They ..also change the 



* Proc. Acad. Nat. Sci. 1850, p. 21. 

 t Am. Jour., July, 1867, p. 40. 

 t Proc. Acad. Nat. Sci. Phil., 1859, p. 16. 

 § Proc. Acad. Nat. Sci. Phil., 1858, p. 44. 

 I! Am. Jour., Nov., 1867, p. 331. 



