124 
INDEX. 
Page. 
Pinkerton, T., cited 36 
Pirsson, L. V., cited 47, 86 
Pumpelly, 31., cited 27 
Quartz in quartz-porphyries, character 
of 40-41, 45 
Quartz-porphyries, characters and distribu- 
tion of 39-42 
description of 39-42 
Raccoon Creek, description of amygdaloids 
from 56 
Reiser, cited 68 
Reusch, H. H., cited 08 
Reyer, E., cited 68 
Rhyolitic structure in aporhyolites, charac- 
ters of 54-55 
Rogers, H. D., cited. . . . 14-16, 21, 23, 25, 66, 71, 82, 83 
Rosenbusch, H., cited 35, 36, 37, 46, 57, 64, 68, 84 
Roth, Justus, cited 36 
Rutley, F., cited 40, 54 
Sauer, cited 59 
Schopf, J. IX, cited 14 
Sedimentary rocks, description of 21-22 
Sericite schist, localities of 64-66 
Shaler, 1ST. S., cited 86 
Slates, localities of 43, 64-66, 79-80 
Page. 
Smith, G. O., volcanic rocks in Maine 
studied by 86 
Sorby, H. C, cited 31 
South Mountain, area of 13 
account of surveys in 14-19 
Spherulitic structure in aporhyolites, char- 
acter of 43-44, 51-54 
Suess, Eduard, cited 68 
Taxitic structure of rocks, description of. . . 57 
Teall, J. J. Harris, cited 37, 47, 68 
Tietze, cited 68 
Tornebohm, A. E., cited 31 
Trimble, Henry, analyses by 61 
Tyson, P. T., cited 10, 24, 25 
Van Hise,C.R., cited 31 
Vogel, C . , cited 59 
Vogelsang H., cited 59 
Wadsworth , M. E., cited 60, 86 
Walcott, CD., cited 21.22 
Wallerius, cited 36 
Williams, G. H., letter of transmittal by. . 11 
cited 13, 29, 41. 42. 47, 64 86 
Voung, A. A., cited 31 
Zirkel, F., cited 36, 49, 54 
V 
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