276 J. D. Dana on the Quartzite, Limestone, etc., 
Stromatopora, Chetetes and Stictopora. Two kinds of encrinal 
plates have also been discovered. These genera were determined 
by Prof. James Hall. 
Euomphalus. This is a genus of univalve mollusks, somewhat 
resembling Maclurea and Ophileta. It is most common in 
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 limestone in Orwell, which is quite 
near the locality in Sudbury. There are two species of Euom- 
8. 
semi-crystalline limestone connected with clay slate upon Lake 
Memphremagog near talcose schist. We cannot ourselves dis- 
phremagog and the Eolian limestone. This genus occurs mm 
dark colored slaty limestone in Sudbury and Cornwall, associated 
Stromatopora. is is the most common of all the fossils in 
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. ere are 
probably two species of Stromatopora in the Eolian limestone. 
_ Chetetes. This genus is both an early and late one—that is, it 
is found from the Lower Silurian to the Carboniferous — 
olian 
mon at Peck’s quarry in Cornwall, and on Dea, Casey’s farm; 
at New Haven on the railroad north of New Haven railroa 
bridge, and in a loose block of limestone at Middlebury village. 
vetopora. Sudbury were also collected specimens of the 
genus Stictopora. This genus was remarkably well defined. Prof. 
Devonian rocks, : The fragments of small encrinal stems that have 
been gece sey in a Eolian limestone, were found at he — FA 
uarries in East Dorset, upon Mt. din West Rut 
aa and Cornwall, — ee eae er 
