U.S. #UX278a FDC Endangered Species

U.S. #UX278a Mint -Endangered Species - Booklet with complete set of 15 Postal Cards (#264-278) featuring the commemorative First Day of Issue cancel

Franked and Pictured on the cards are the Black-footed ferret, Schaus swallowtail butterfly, Brown pelican, San Francisco garter snake, Ocelot, Gila trout, Hawaiian monk seal, Thick-bille parrot, California condor, Wyoming toad, Woodland caribou, Florida manatee, Piping plover, Florida panther, and American crocodile.