114 ME. E. H. WORTH OX THE [vol. lxx\% 



EXPLANATION OF PLATES V-VIH. 



Plate Y. 



Fig. 1. Chiastolite. London & South-Western Railway Quarry. LXXVL 

 S.E. 57. X 46. (See p. 82.) 



2. Garnet. Quarry No. 1, near Bedaven. Q.I, 77. Crossed nicols. 



X 21. (See p. 85.) 



3. Idocrase, zoned. Dr. E. H. Young's slide. T.J. 4. Crossed nicols. 



X 19. (See p. 85.) 



4. Scapolite. Quarry No. 1, near Bedaven. Q. I, 65. X 32. (See 



p. 85.) 



5. Lepidolite-rock. Quarry No. 1, near Eedaven. Crossed nicols. X 30. 



(See p. 86.) 



6. Badiolarian, from chert-inclusion in ' dark igneous ' rock. South 



Down. LXXYI, S.E. 77. X 80. (See p. 88.) 



Plate VI. 



Fig. 7. Felsite with micropegmatite, near Forest Mine. LXXYI, S.E. 25. 

 Crossed nicols. X 20. (See p. 88.) 



8. Junction of radiolarian chert and vein from ' dark igneous ' rock. 



London & South-Western Eailway Quarry. LXXVI, S.E. 59. 

 X 11. (Seep. 96.) 



9. Polished surface of agglomeratic ' dark igneous ' rock, from London 



& South- Western Eailway Quarry. LXXYI, S.E. 56. X 2|. (See 

 p. 94.) 



10. Deformed shale-inclusion in 'dark igneous' rock from Loading Bank. 



LXXYI, S.E. 15. X 12. (See p. 96.) 



11. Band of microlites in homogeneous ' dark igneous ' rock, from 



Loading Bank. LXXYI, S.E. 15 c. Crossed nicols. X 33. (See 

 p. 94.) 



Plate Y1T. 



Fig. 12. Meldon aplite, standard from Quarry No. 1. Q. I, 70. Crossed 

 nicols. X 27. (See p. 103.) 



13. Meldon aplite, chilled rock at contact, azure-coloured. Quarry No. 1. 



Q. I, 42. Crossed nicols. X 27. (See p. 104.) 



14. Felspars in Meldon aplite. normal to junction with igneous inclusion. 



Quarry No. 3. Q. Ill, 78. Crossed nicols. X 20. (See p. 104.) 



15. Fluorspar in mica, from coarse vein in Meldon aplite. Quarry 



No. 1. Q. I, 61. X 42. (See p. 105.) 



16. Tourmaline moulded on felspar, in Meldon aplite. Q.I, 25. X 23. 



(See p. 107.) 



17. Anthophyllite in shale-inclusion in ' dark igneous ' rock, from 



Loading Bank. LXXYI, S.E. 15. X 47. (See p. 94.) 



Plate YIII. 



Geological map of the Meldon Yalleys, on the scale of 6 inches 

 to the mile, or 1:10,560. 



DlSCESSIOX. 



The President (Mr. G. W. Lamplegh) complimented the 

 Author upon his clear exposition of a difficult subject. With 

 reference to the peculiar characters of the ' dark igneous ' rocks, 

 he was reminded of the work of his former colleagues in Ireland, 

 Mr. J. E, Kilroe & Mr. A. McHenrv, who had observed intrusive 



