</a> Courtesy Smithsonian Institution National Numismatic Collection. Rare Currency at The Smithsonian The previous coin's older brother the 1849, Gold Rush era double eagle gold coin is valued by collectors the world over. It was the United States of America's first $20 denominational gold coin. Courtesy Smithsonian Institution National Numismatic Collection.
subspecies - (biology) a taxonomic group that is a division of a species; usually arises as a consequence of geographical isolation within a species. race. biological science, biology - the science that studies living organisms. taxon, taxonomic category, taxonomic group - animal or plant group having natural relations.
taxon, taxonomic category, taxonomic group-animal or plant group having natural relations. family - (biology) a taxonomic group containing one or more genera; sharks belong to the fish family. subgenus - (biology) taxonomic group between a genus and a species.. (Biology) biology any of the taxonomic groups into which a family is divided and which contains one or more species. For example, Vulpes (foxes) is a genus of the dog family (Canidae).