48 LIST OF CONTRIBUTORS. 



Frazer, Persifor. Jr. Continued. 



On thin sections of the traps of the Mesozoic basin. P '75, 72 



■ On the character of the Lower Silurian slate at their out- 

 crops. P '75, 76 



On the Trias of York County, Pa. P '75, 123 



On the structure of the York County Valley limestone and 



on micro-photography of minerals. P '75. 128 



On the Mesozoic Red Sandstone of the Atlantic States. P 



'75, 440 



On dialysis in oyster culture. P '75, 442 



On heat and chemical action. P '75, 444 



— ■ On the age and origin of certain quartz veins. P '76, 36 



Notes on some palaeozoic limestones. P '76, 60 



Notes on two traps : A case of alteration of earthy sediments. 



P '76, 60 



— On the microscopic observation of minute objects. P '76. 84 



— On certain trap rocks from Brazil. P '76, 119 



— On the Hudson River and Utica slates of Pennsylvania. 

 P '77, 14 



— ■ Anthracite from " Third-Hill Mountain." West Virginia. 



P '77, 16 



— On copper-bearing rocks of the Mesozoic formation. P '77, 17 



— Contamination of drinking water. P '77, 19 



— Two supposed new trap dykes in Chester County, Pennsyl- 

 vania. P '96, 206 



— Geological section from Moscow to Siberia and return. 



P '97, 405 

 — History of the Caribbean Islands from a petrographic point 



of view. (Abstract). P '03, 396 



Gabb, William M. Descriptions of two new species of Carboni- 

 ferous fossils brought from Fort Belknap, Texas, by Dr. Moore. 

 P '59, 297 



Catalogue of invertebrate fossils of the Cretaceous formation 



of the United States. P '59, App. 



Descriptions of new species of Cretaceous fossils from New 



Jersey. P '60, 93 



— Descriptions of some new species of Cretaceous fossils from 



South America. P '60, 1!>7 



— On the identity of Ammonites texanns Roe me r, and A. ves- 

 pertinns Morion. I* *(i(), 202 



