Kinahan — On Irish Marbles and Limestones. 395 



King's Co. 



Near Clonmacnoise, Wilkinson records " a beautiful marble of 

 Sienna character." It is easily worked, and has been frequently 

 used for ornamental works, and " deserves to be more generally 

 known than it at present is." This stone, although of Sienna 

 character, is not of Sienna colour, it being more of a purplish- 

 clouded grey. 



Tipperary. 

 Among the marbles mentioned by Kane as occurring near 

 Dunkerron are some of yellow colour, and veined. 



METAMOEPHIC KOCKS. 



The rocks next to be enumerated are probably metamorphosed 

 Ordovicians (Cambro or Lower Silurians) or Cambrians, generally 

 the latter. 



These marble-bearing stones must be subdivided, as one class 

 was originally limestone or dolomyte, while the other was volcanic 

 rock, exotic rock, or those allied to them. The latter have to be 

 included, because, as previously pointed out, they, and also certain 

 peculiarly altered limestones and dolomytes, are generally classed 

 together under the common name of Serpentine, both the lime- 

 stone and volcanic rocks having undergone a secondary change, 

 due to a chemical action from without, which has been called by 

 Dr. King, of Gralway, Methylosis. The limestones that have only 

 undergone simple metamorphosis (mineralized and micaised) will 

 be classed as metamorphic limestones; while the chemically changed 

 limestones and exotic rocks will be grouped together. 



The subdivision of the Methylotic rocks is of such recent date 

 that, from the available records, it is hard to accurately sub- 

 divide them unless all the localities were personally revisited. Tho 

 subdivisions given hereafter are therefore in part only suggestive v 

 but, as far as possible, they will be oorrect. 



