JEFFERSON COUNTY. 



403 



it covers very freqiientl}' large surfaces. The parts are usually detached from each other, in 

 consequence of the destruction of the ligament wliicii binds the columns together. We find 

 merely a single ring imbedded by itself in the shale ; and though tiiey are extremely abundant 

 at Loraine, yet the heads of the animal are exceedingly rare. Its specific name is derived 

 from Hampton, where it was first discovered. It is equally abundant at Pulaski and Saratoga, 

 and indeed wherever this mass has been examined in New-York. The head and the parts 

 surrounding it are very diminutive and delicate, in comparison with the size of the vertebral 

 colunm. 



112. 



1. Trinucleus caractaci. 



2. Strophomena. 



3. Strophomena nasula. 



4. Cypricardiles modiolaris. 



No. 1. The first fossil of this group was found towards the upper part of the loraine shales, 

 in a very fine bluish slate. The bed was exposed in repairing a mill-dam near the centre of 

 Loraine ; and judging from the fragments thrown out, thousands must have occupied this 

 location. They are very perfect at this locality, the animal being entire in all its parts. I 

 have preferred to consider this as the same fossil figured by Murchison in the Silurian System, 

 and belonging to the Caradoc sandstone, though some slight differences appear to exist. The 

 spines of the buckler in the Loraine fossil, are twice the length of the body and tail ; but in 

 the figures of Murchison, they are considerably shorter, which circumstance I suppose may 

 have arisen from the imperfection of the specimens. 



The Trinucleus of Loraine is clearly distinguished from the one in the trcnton limestone, 

 by the width of the perforated margin of the buckler, the number of perfect circles of perfo- 

 ration, and the length of the spines. Some of the individuals are one-third larger than the 

 drawing, which is the average size of the petrifaction. 



No. 2. This Strophomena is common upon the same surface with the following, but it is too 

 much rounded to be the flat valve of that species. One which strongly resembles it, is found 

 deep in the mass of shales. 



