100 PROCEEDINGS OF SOCIETIES. 



sideration of the distortion of fossils, confirm several of his results, which 

 were obtained principally from microscopic examinations of cleaved 

 rocks. One of the most interesting of our agreements relates to the 

 great amount of compression occasionally occurring in cleaved rocks, 

 which I have shown to amount to 1 and 1 1 degrees of relative com- 

 pression at Tintagel and Garth — an amount of relative compression con- 

 sistent with Mr. Sorby' s observations, who has commonly observed 6 de- 

 grees of compression in well-cleaved rocks. There are several points of 

 difference between my results and those of both Mr. Sharpe and Mr. 

 Sorby, which will, no doubt, be cleared up by further research. The 

 chief discrepancy between us is the following: — Both Mr. Sorby and Mr. 

 Sharpe have observed an elongation in the line of dip (of cleavage ?) ; 

 an appearance which I have not found in any case, except that of South 

 Petherwin, where it exists, but to a very small extent, and can only be 

 discovered by calculation, as it is not sufficiently decided to be very sensi- 

 ble by direct observations. 



- ON THE SUBDIVISION OF THE CARBONIFEROUS FORMATION OF IRELAND. 

 BY JOHN KELLY, ESQ. 



In the present paper I mean to treat of the several subdivisions of 

 the Carboniferous formation in Ireland. While my chief object is to draw 

 attention to one or two of those subdivisions, especially the supposed 

 calp of Dr. Griffith, and in this case having, according to my views, to 

 deal with an imaginary band of rock, I must be more particular than if 

 I had a real tangible subject, which, in one part of the country, could be 

 compared with other parts of the system. I mean to show that every- 

 where in Ireland this rock is mentioned as existing, it is a group of an- 

 other part of the formation that is mistaken, and introduced into that 

 place. 



Before I proceed further, I will here observe, that it is not without 

 some reluctance I stand up in this place in opposition to the views of Dr. 

 Griffith— a gentleman with whom, I may say, I spent my whole life, 

 and with whom I gained my own geological experience. He would be 

 one of the first himself to join in correcting an error, if he were convinced 

 of that error. From the great desire there appears to exist among geo- 

 logists of eminence, within the last dozen years, to have the honour of 

 founding new systems, and the confusion and drawback to the progress 

 of the science consequent upon it, I believe there is no really good, un- 

 exceptionable system of the classification of rocks yet arrived at in Geo- 

 logy. It is a new science with us all ; and many of its facts are capable 

 of two or more interpretations. One man may account for a fact dif- 

 ferently from another ; and it is from conclusions drawn from the expe- 

 rience and views of different persons, in several countries, that we may 

 expect to arrive at a satisfactory settlement of opinions on the subject. 

 My convictions happen to be different from those of Dr. Griffith on the 

 subject of his calp ; and, however unwilling I may be to differ from 

 him, it appears to me to be the duty of every member of this Society, 



