PRE-CA1TBEIAX ROCKS OF ST. DAVID'S. 333 



prove the author's views as to the relations of the beds. Dr. 

 Hicks's views as to the remanie character of the tuffs alternating 

 with the conglomerate were contradicted by the careful study of Drs. 

 Zirkel and AYichmann and M. Renard. Dr. Hicks had been recently 

 to St. David's, but he was quite unable to produce a pebble of Di- 

 metian from the Conglomerate. He controverted Dr. Hicks's views 

 as to the section at Ogof-llesugn. He stated that the diabase dykes 

 cut through both the granite and the Cambrian conglomerate of 

 the district, though they are most abundant in the former. In reply 

 to Prof. Bonney, he stated that microcline was regarded by conti- 

 nental workers as characteristic of granite rather than of gneiss. 

 He asserted that none of the conclusions of his paper had been 

 shaken by the discussion. He disclaimed all wish to interfere in 

 this controversy in the first instance ; but it was from a sense of 

 duty that he came forward and defended the views of his pre- 

 decessors. 



