How did east egg and west egg get their names?

East Egg and West Egg are two peninsulas that, from the air, resemble eggs "flattened at the contact end." Gatsby and Nick live at West Egg; Daisy and Tom at East Egg, the wealthier and more fashionable of the two. Fitzgerald based the two locations on real places on Long Island Sound, Great Neck (West Egg) and Manhasset Neck (East Egg).