If you've ever bitten into the sweet, pastel orange flesh of a melon with a gray webbed rind and thought to yourself, "Yum, cantaloupe," you were wrong. Not about the deliciousness, but about the name of the fruit. A "real" cantaloupe, or at least the original bearer of the name, is a European cantaloupe. What Americans think of as cantaloupe is a different fruit.
The things Americans and Europeans think of as cantaloupes belong to a category of melon called musk melon. As summed up by an instructor at the University of Illinois, "All cantaloupes are musk melons, but not all musk melons are cantaloupes." And the category of "musk melon" contains a whole lot of other melons, including honeydews and Armenian cucumbers.
The European varietal's proper name is Cucumis melo cantalupensis, while the American varietal is Cucumis melo reticulatus. The European name for the melon comes from the area near Rome called Cantaluppi, a former papal seat, where the fruit was "grown after being introduced from Armenia." Hence, the original "cantaloupe." The European varietal has wartier, unnetted pale green skin with a hard rind and deep vein tracts.
On the other hand, the name for the American varietal—reticulatus—refers to its "retriculated" or netted appearance. (You can understand why "retriculated melon" didn't catch on as a name.) Most botanists and horticulturists say that it's most accurate to just call American cantaloupes by their family name: musk melon. You may not be the most precise, but you're not wrong either. However, Australians and New Zealanders might have a better idea: They tend to call this kind of fruit a rockmelon, due to its craggy appearance.
So, until Americans come up with a better name for our particular kind of cantaloupe, we're pretty much stuck with eating a kind of imposter. A very delicious imposter.