TABLE OF CONTENTS. 



Pages. 



Preliminary considerations 607-609 



Family GEOMYID^E 609-011 



Genus Geomys 611-012 



Geomys bursarius 012-614 



tuza 615-616 



castanops 616-617 



mexicanus 617-618 



hispidus 619-621 



Genus Thomomys ■. 621-623 



Thomomys talpoides 023-625 



bulbivorus 626-627 



umbriuus 628-628 



clusius 629-629 



605 



