FOSSILS. 419 



Euomphalus. This is a genus of univalve mollusk, somewhat resembling Maclurea and Ophileta. It is 

 most common in the Devonian and carboniferous rocks, though not wanting in the lower Silurian. This 

 genus has been collected from the Eolian limestone in Whiting and Sudbury. A shell of the same genus 

 is found in the Hudson River limestones in Orwell, which is quite near the locality in Sudbury. There are 

 two species of Euomphalus in the Eolian limestone. 



Zaphrentis. The three other genera are of corals. Zaphrentis belongs to the family of Cyathophylidce, 

 and there is no instance in this country where this genus has been found below the horizon of Atrypa 

 reticularis, which is an upper Silurian and Devonian species. The two are found together in great abundance 

 in the semi-crystalline limestone connected with clay slate upon Lake Memphremagog near talcose schist. 

 We cannot ourselves distinguish between the specimens of Zaphrentis from Lake Memphremagog and the 

 Eolian limestone. 



This genus occurs in a dark colored slaty limestone in Sudbury and Cornwall, associated with Euomphalus 

 and Chajtetes. 



Stromatopora. This is the most common of all the fossils in the Eolian limestone, and it is a genus 

 whose lower limit is in the Niagara group of upper Silurian rocks. It has been found in Sudbury, Orwell, 

 Cornwall, East Middlebury, Brandon, New Haven and Williston. The specimens from East Middlebury 

 and Williston are referred to this genus with a query. There are probably two species of Stromatopora in 

 the Eolian limestone. 



Chcctetes. This genus is both an early and late one that is, it is found from the lower Silurian to the 

 carboniferous rocks. Both branching and oval forms of this genus occur in the Eolian limestone of Vermont, 

 and there are two distinct species of it. It has been found in Sudbury, Benson, on M. C. Bice's farm, 

 Cornwall and Williston. 



A supposed fossil of this genus is quite common at Peck's quarry in Cornwall, and on Dea. Casey's farm; 

 at New Haven on the railroad north of New Haven railroad bridge, and in a loose block of limestone at 

 Middlebury village. 



In Sudbury were also collected specimens of the genus Stictopora. This genus was remarkably well 

 defined. Prof. Hall did not venture to pronounce upon the species. 



An , obscure coralline form, distinct from any of the others described, has been found in the limeston- 

 above Sheldon & Slason's marble quarry, in West Rutland. 



The large encrinal stems from Sudbury and Cornwall are interesting, because the only cases where 

 encrinal rings of such dimensions have been found in this country are in Devonian rocks. 



The fragments of small encrinal stems that have been discovered in the Eolian limestone, were found at 

 the marble quarries in East Dorset, upon Mt. Eolus, and in West Rutland, Sudbury and Cornwall. 



One will be struck with the fact that all these fossils have an upper Silurian or Devonian character, 

 wherever they are of value in identifying strata. 



Geological Position, Origin, and Equivalency* 



We quite despair of satisfying ourselves or others on these points in respect to the 

 Eolian limestone. The facts are very remarkable, but we doubt whether we have been 

 able to seize upon the fundamental principle that will harmonize and explain the whole. 

 When we throw out our suggestions, let it not be thought that we are very tenacious of 

 them. We have tried to work out the relative position of this formation and its charac- 

 ters, so that our maps and sections will show them. But how the strata came into the 

 positions they now occupy, is a question of great difficulty. Our facts, we trust, will be 

 of service to future explorers ; but we cannot hope as much from our hypotheses. 



Mount Eolus contains, as already remarked, the most remarkable development of white 

 limestone in New England. As we ascend its eastern face from East Dorset, we shall 



*By E. Hitchcock, Senior. 



