Gongylophis and Eryx are two genera in the family Erycinae, the main difference is where the species within the genus live, Gongylophis is essentially Middle Africa, which is is below Egypt, and it includes India, Pakistan, Sri Lanka, and Bangladesh (Eryx johnii comes from India and Pakistan, but it is considered in the genus Eryx) so Eryx conicus is actually a "mislabeled" name for Gongylophis conicus which is the correct scientific name for the Rough Scaled Sand Boa which hails from the region of India, and Pakistan