Iguana, a genus of tree-lizards, with five species from the Antilles and South America, the type of a family (Iguanidce) with fifty-six genera, from the Neotropical region. They feed on leaves, fruit, and, to some extent, on insects. In the type-genus there is a pouch under the throat, and a row of spines extending from the neck to the tip of the tail. The common Iguana is green in colour and from 3 feet to 5 feet long; its eggs and flesh are used for food. It enters the water readily, and swims with ease, using the long tail as a propeller. To this family belong Amblyrhynchus (the marine lizard described by Darwin), Phrynosoma (the Horned Toads), and Basiliscus (the Basilisks).