a) Biotite from granodiorite (grano-toscanose). El Capitan, Vosemite Valley, 



7. S„ Vol. VII (1899), p. » 9 4. 



b) BtOtite from quartz- tnonzonite (er-ino-toscanose), Nevada Falls Trail, ' 



Valley, Cal. A. J. S., Vol. VII (1899), p. 297, and Bull. lbS, U. 



5 r. 1 . ■., |i. 208. 

 t) Biotite from quartz-montonite (grano-amiatose), Walkcrville Station, Hull 



|0i 1 . Gbol., Vol, VII, and Bull, 1O8, U. S. Geo!, S«rv., p. 116. 

 d) Bioiiie from quartz-mon oniit (grano(?)ioscanose). Bloods Station, Al 



Cal. A.J. S. Vol. VII (1899), p. = 94 . 

 t) Lepidomelane from granite (grano-liparose), Cape Ann, Mass. A, J. 



XXXII. 1886, p. 359. Rock analysis, H. S. WASHINGTON, Jour. Ge0i.„ 



P 93 



/) Lepidomelane from nephelite-syeniie (grano-nordmarkoM), Litchfield, Me. Bull. 



JbS, <". S. Ceo/. Surv. t p. 21. 

 g) Lepidomelane from syenite-pegmatite, Itarkcvik, La ngesnnd fjord. Norway J rocli 



analysis from laurdalite (laurdalose), north of Love, Laugcnthal, BrScgbr, 



Eruptivgest. Kristiania geb. Ill, pp, 19 and ; ». 

 //) Lepidomelane from (?) nepliclite-syenite, Minsk, Dana, System, p, 630 ] rocl< analysis 



from miascit (grano-miaskose), Mt. Lobatchia, Siberia, \. Rari'inski, 



Guide Exeurs. Vll, Cong. Geol. Int. V (1897), p. 3a. 

 i) " Biotite " from monchiquite, Horberig, Oberbcrgen, Rosbndi !CH» El. Gest,, p. 934. 

 j) Phlogopite from wyomingitc (phyro-wyomingosc), Boar's Tusk, Leucite Hills, Wyo. 

 I. /. \., Vol. IV (1897), p. i 3 o,and Bull. 168, I ., p. S S - 



TABLE XlVa, MOLECULAR RATIOS IN MICAS. 



.j) Biotite 



b) Biotiti 



.i Biotit. 



rf) B 



t) Lepldomeli 



/ t Lepldo nel 



i') Lepldomel 



n 1 Lepid '■ 



i 1 Phloj '■! "■ 



gr.imiliparose 



gr.11111 mmlmarkose 

 gr;)[in.l;nir«lalosr . . 

 grjiiomiaskose . .. 



phyro-wyoniin^ii.f 



:::; 



Gn 



Ni'i-ln'lite-syenite . 



Nephelitr 



Wyomingite 



