LETTER OF TRANSMITTAL UNITED STATES GEOLOGICAL SURVEY, SIR: I have the honor to transmit herewith a paper on Secondary Enlargements of Mineral Fragments in Certain Rocks, prepared by myself and Assistant Geologist C. R. Van Hise. The plates were all drawn from nature with the camera lucida, by Assistant Geologist W. N. Merriam. I am, sir, very respectfully yours, ROLAND D. IRVING, Geologist in Charge of the Survey of Hon. J. W. POWELL, Director United States Geological Surrey, (189) Washington, D. C. 5 |