IGNEOUS AND CRYSTALLINE ROCKS. 23 
Analyses M, N, by George Steiger, record No. 1975. 
O. Quartz diabase, west of Ashley reservoir, Holyoke. Vaalose. Contains calcite 
and radiated quartz. P. R. ©. 1653. 
P. Palagonite, from blebs in O. 
Analyses O, P, by Steiger, No. 2039; rocks described by Emerson in Bull. Geol. 
Soc. America, vol. 16, p. 91. 
Q. Granite gneiss, Hoosac Mountain. Toscanose. Contains quartz, microcline, 
albite, muscovite, biotite, magnetite, titanite, epidote, apatite, and zircon. Analysis 
by E. T. Allen, record No. 2064. P. R. C. 1718. 
R. Albite schist, Hoosac Mountain. Varingose. Same minerals as in Q, with 
garnet and pyrite. Same analyst and number. P. R. C. 1719. 
Rocks Q and R collected by J. E. Wolff, but not yet described. The following 
feldspars, all albite, separated from schists of the same region, are described by Wolff 
ir Mon. XXIII, pp. 60 and 187. Analyses by R. B. Riggs, record Nos. 507 and 567. 
8. From feldspathic schist, central shaft of the Hoosac tunnel. P. R. C. 129. 
T. U. From the porphyritic mica schist of Greylock Mountain. 
Ke 
Ho 8b 105 ss ecanicen.s 
@ Fe2O3 less than 0.5 per cent. > Loss on ignition. 
V. Pyroxene-titanite aplite, South Peru. Analysis by W. T. Schaller, record 
No. 2143. 
W. Diorite, railroad cut west of Ironstone. Analysis by E. (. Sullivan. 
X. Pre-Cambrian quartzite gneiss, Northbridge. Analysis by Sullivan. 
Rocks V, W, X, collected by B. K. Emerson, but no description furnished. 
