10 ILLUSTRATIONS. 



PAGE. 



Plate XX. A, Plication in shaly purplish red limestone of early Tertiary (?) age 

 along Rio Ocoa; B, Tilted beds of purplish red limestone near sup- 

 posed oil seep on Arroyo Salado 226 



XXI. Index map of Dominican Republic showing mining concessions in 



force in July, 1919 228 



XXII. Map of Sierra Prieta at " Perseverancia mine" 232 



XXIII. Map of part of the San Francisco concession, San Cristobal mining 



district 236 



