A. R. Sunt — Age of the Dartmoor Granites. 



103 



On the second cut (Fig. III.) are drawings selected from six 

 specimens, of which the five lower ones deserve special notice, viz., 

 commencing with the lowest: — 



(1) Quartz vein in Culm slates, valley below Becky Falls. 



(2) " Ditsworthy — vein is intrusive in a tongue of slate which 

 extends into the granite across the Plym valley from Kingmoor — a 

 very narrow strip." (Worth.) 



Quartz, decomposed felspar, white mica, brown tourmaline decora- 

 posing into green. A very remarkable rock, with inclusions (as 

 shown above) varying to the utmost extreme. 



Fig. IV. 



(3) Blackinstone Quarry, and (4) Honey bag Tor, ordinary 

 granites. 



(5) Hamel Down, quartz-felspar-tourraaline vein ; negative crystal 

 apparently based on the rhomboidal prism. 



