J. B. Perry on the Geology of Vermont. . 349 
a 
hdstone. But, if such be the ni how could any mistake 
arise? First, the rocks are very complicated, and cannot be 
_Inastered without much study and long continued observation. 
Next, nothing is easier than misunderstanding. In speaking 
to Mr. Billings of the Georgia Group as containing Conoceph- 
dites Teucer, Olenellus, etc., I said, among other things: 
These slates are interstratified with sandstone. From this he 
inferred, as was afterward evident from one of his articles, that 
others, he cited me in connection with Dr. G. M. Hall as 
3 this Journal for January, 1862, (vol. xxxii, p. 100.) In this 
he did what was very natural under the circumstances, since 
| P Sandstone falls to the d 
tT ground, Be 
| Such is a brief exposition of a single point in the Geology 
a of cotorn Vermont, In due time other points may be ex- 
