OPHITIC TEXTURE 649 



(5) Where weathering goes on faster than erosion, the rock is often broken 

 down into a coarse gi-avel, each grain of which is likely to be a single augite 

 crystal. 



(6) The thin-section (figure 3, plate 70) shows the texture plainly, and 

 how it is produced by the fact that the augite, while readily enveloping the 

 labradorite, crowds ahead of it the corroded remnants of the olivine (at 

 whose expense it is formed) as well as the iron oxide. 



The following paper Avas then read hj title : 



OCCURRENCE OF DIAMOyDS IN NORTH AMERICA 

 BY GEORGE F. KUNZ 



The following paper was then read : 



SILVER-GOLD ORES AT SAN PEDRO DE GUANACEVI. DVRANGO, MEXICO 



BY FREDERICK B. PECK 



The following paper was then read by title and transferred with per- 

 mission of the author to Section E, American Association for the Ad- 

 vancement of Science, and read there December 31. 



PERSPECTIVE VIEW OF THE SUBMARINE CANYON OF THE HUDSON RIVER 



BY J. W. SPEj?irCEB 



The following papers were read by title ; 



TITANIFEROVS BASALTS OF THE WESTERN MEDITERRANEAN 

 BY- H. S. WASHINGTOKT 



THE PALEOZOIC SECTION OF THE UPPER YUKON 

 BY A. H. BROOKS .^ND E. M. KINDLE 



STRATIGRAPHIC SUCCESSION NORTH OF COOK INLET, ALASKA 

 BY SIDNEY PAIGE AND ADOLPH KNOPP * 



This paper appears as pages 325-332 of this volume. 



SEISMOLOGICAL OBSERVATIONS OF THE UNITED STATES 

 BY H. F. KEID 



The following paper Avas read by title and was transferred Avith per- 



* Introduced by A. H. Brooks. 



