ON THE CRYSTALLINE KOCKS OF ANGLESEY. 



285 



Auff. 18iV.Tr. 



SiO., 

 ALO, 

 ¥e.,6, 

 Feb . 

 CaO . 

 MgO . 

 K,0 . 

 Na.,0 

 HjO . 



No. 223a. Jmi)ery Phyllite. 

 In Limestone, ^QOfeet S.W. (a, little to W.) of Hendrchach. 



99-21 



09-7.5 



A ' jaspery phyllice ' — that is, a peculiar red or purple shale closely 

 associated with the jaspers and limestones. This example is from a 

 complex mass, chiefly limestone , near Cerrig Ceinwen, A jasper from 

 the same complex was analysed last year. 



No. 425a. Gahhro. 



10017 



99-7E 



In the above I'ock HgO (above 110°) was determined by finding loss 

 of weight on ignition. 



A specimen taken from the least deformed portion known to me of 

 the gabbro of Holyhead Island. The serpentine of that complex was 

 analysed many years ago by Mr. F. T. S. Houghton.^ 



No. 429a. Limestone. 

 Ang. 11 S.E. IQQfeet 8.8.E. of Cerig Moelion. 



A peculiar dark, hard limestone that occurs in association with the 

 same serpentine and gabbro. This rock i.s not the ophicaloite, which T 

 hope later on to deal with. 



' See Bonney, Q.J.G.8., 1881, p. 46. 



