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INSTITUTO GEOLÓGICO DE MÉXICO. 



I lime the homar to forman! herewHh a copy of the 

 Bnlletin of the Geological Institufe of México. 



Kindly acknowledge receipt upon the accompanyny 

 cm-d. didy signed and dated. Failure to acknowledge pn- 

 hlirations loill be looked upon as an indication that fiir- 

 ther exchanges are not desired. 



Contributions in exchange for the Library of the Ins- 

 titiíte, are respectfuUy solicited. 



I am, íS'¿>, 



Your obedient aervanf, 



Address: 



Instituto Geológico fie México. 

 5? Ciprés 272S. 



México, D. F. 



México, 



