20 
Transactions Texas Academy of Science. 
freely givon^ and to the Hon. Jefferson Johnson, 'Commissioner of Agri- 
cnltnre, Insurance, iStatistics and History, for courtesies shown me while 
prosecuting the work. To Professor Kobert 'T. Hill, of the United 
States Geological Survey; Professor Gilbert D. Harris, of 'Cornell Uni- 
versity, and to Mr. W. Kennedy, of Austin, I am greatly indebted for 
publications unknown to the ordinary reader, and not easy to obtain. 
My thanks are also due Librarian Wyche, of the University, both for 
suggestions and valuable assistance. F. W. S. 
December, 1899. 
Publications marked with a star (*) have not been examined by the 
Compiler. 
