What designates the subspecies *Carphophis amoenus amoenus* within the Eastern Worm Snake?

It is the nominate subspecies, typically referring to the population originally described by the species author

Taxonomic classification extends to subspecies to denote finer regional variations within a single species where populations are geographically separated but still capable of interbreeding. The designation 'nominate subspecies' holds a specific meaning in nomenclature. When the subspecies epithet is identical to the species epithet, as seen in *Carphophis amoenus amoenus*, it signifies that this particular population—the one sharing the exact species name—was the very first one studied, documented, and described by the original authority who established the species name itself. This level of classification highlights consistent, albeit minor, differences in traits like scale counts or pattern intensity compared to other, non-nominate subspecies within *C. amoenus*.