Geological Reports of the State of New York. 233 



Murchison's work on the Silurian system had not appeared, and 

 the field was new and to a great extent unexplored. After all 

 that had been accomplished by Prof. Eaton in his survey of the 

 strata along the Great Western Canal, and by others, the explo- 

 ration, as connected with general geology, could scarcely be said 

 to have been begun. Probably others yet remain to be accom- 

 plished. Too many groups may have been formed. While Cryp- 

 tolithns tesselatus retains its place with some others in the Llan- 

 deilo flags and in the lower part of the Trenton limestone, and 

 in that of the Mohawk at Fonda and in other places, that rock of 

 Wales may yet find its equivalent in our series. The greater 

 number and variety of our groups may not involve all those de- 

 scribed by Murchison, but only the fullest examination should 

 be satisfactory. 



Finally. The discoveries which have been made by the pale- 

 ontologist. These are many, and of great interest. Omitting all 

 the organic remains which have been identified with the Euro- 

 pean, and the many new genera and species, there are several 

 general facts of great value. 



First : The identifying of the sandstone of Blossburg, Penn. 

 with the old red sandstone of Europe, a part of the Devonian 

 system. The geological positions of the two rocks are very 

 nearly or quite the same ; and the remains of the fish, Holopty- 

 chus nobilissimus, found before only in the old red sandstone, 

 seem to settle the point conclusively. The stumbling block of 

 our geology is thus removed. The Blossburg sandstone is the 

 upper part of the Devonian system. The Chemung group, as it 

 is called in the geological reports, forms the lower part 'of the 

 Devonian, and is characterized by the same shells, pp. 42 and 43. 



Second: The carboniferous system in Pennsylvania and Ohio, 

 contains many species of shells found in the same system in 

 Europe. Even "at Engineer Cantonment, Missouri River," the 

 shells of the carboniferous system are found, as well as at Pitts- 

 burgh and on the Alleghany Mountains. Eleven species are 

 named as common to the carboniferous strata in our country and 

 Europe, p. 43. 



Third : " Well characterized and undoubted oolite, in the state 

 of Ohio," is for the first time announced in this report, p.. 44. 

 " Two European species of Trigonia, both of which are re- 

 stricted to the oolitic system," are presented as the proof. It has 



Vol. XLii, No. 2.— Jan .-March, 1842. 30 



