Note 329 — Chapter XVII
Reading edition
An instance of this rock occurs in Kincardineshire, from which the large flat twins of labradorite have been analyzed by Dr. Heddle (Trans. Roy. Soc. Edin. vol. xxviii. (1879), p. 257).
[330] C. T. Clough, "The Cheviot Hills," Mem. Geol. Survey (1888), p. 12.