Allen, J. A. (Joel Asaph), 1838-1921.2005-10-062005-10-061901http://hdl.handle.net/2246/499p. 149-188, [4] leaves of plates : ill. ; 24 cm.Includes bibliographical references.Introduction -- Skull and dentition. Sexual variation. Variation due to age, etc. Nasal bones. Supernumerary teeth, and other abnormalities -- Change in color of the ears with age -- Nomenclature -- Synopsis of species and subspecies -- Postscript -- Tables of measurements and ratios.6356969 bytesapplication/pdfen-USQH1 .A4 vol.14, art.11, 1901DidelphisOpossums -- North AmericaOpossums -- ColombiaMarsupials -- North AmericaMarsupials -- ColombiaMammals -- North AmericaMammals -- Colombiatext