156 



present in one part of a crystal and absent from another part of the same 

 crystal, it is difficult to regard it as of much significance. The following is a 

 list of analyses of monoclinic pyroxenes occurring in British rocks of the 

 group now under consideration. 



Xa 2 ... 0-530 ... ... 0-66 ... 



HoO 0-706 0-540 0-60 0-626 0-200 



99-833 100-172 100-16 101-339 100-821 



VI. VII. VIII. IX. 



SiO e ... 51-30 ... 49-268 ... 50-10 ... 48-41 



A1 2 0, ... 0-76 ... 0-222 ... 6-77 ... 4-05 



Fe 2 0, ... ) ( 2-36 



FeO ' ... j 13 ' 92 U - 80 6 ' 90 15-08 



MnO ... 0-25 ... 0-381 ... ... -37 



CaO ... 20-15 ... 20-256 ... 17-46 ... 15-98 



MgO ... 14-85 ... 14-812 ... 17-47 ... 12-14 



K 2 ... ... ... ... 



Na 2 



H 2 O 0-21 0-719 1-30 1-19 



101-44 99-738 100-00 99-58 



I . Green diopsicle. Gabbro. Halival, Isle of Rum. l)r. HEDDLE, Trans. 



Roy. Soc., Edin., vol. XXVIII., 1879, p. 478. 



II. Green diallagic augitc. Sp. Gr. 3-329. Gabbro. Hart O'Corry, Sky e. 



Dr. HEDDLE, loc. cit., p. 479. 



III. Angite. Lock Scavaig, Skye. Dr. HOUGHTON. Dublin Quart. Jour. 



Geol. Soc., vol. V., 1865, p. 95. 



IV. Greyish green diallagic augite. Corry na Creech, Cuchullin Hills, Skye. 



Sp. Gr. 3-329. Dr. HEDDLE, loc. cit. p. 479. 



V. Diallagic augite. Drum-na-Rabn, Cuchullin Hills, Skye. Dr. HEDDLE, 



loc. cit. p. 419. Sp. Gr. 8-880. This augite contained also -380 of Ti0 8 . 



VI. Diallage, Skye. VOM RATH : see Rammelsberg, Handbuch der 



Mineralchernie, 1860, p. 465. 



VII. Dark green diallagic augite. Loch Seavaig, Skye. Sp. Gr. 3321. 



Dr. HEDI>I,R. loc. cit. 



