supported by the elongated hyoid bones. Some are subaquatic in habit. The Moloch lizard, much like a "Horned Toad" in appearance, has long dermal spines.
Oligocene. France [Agama].
Pleistocene. Chlamydosaurus, Australia.
Family Iguanidae. Arboreal, terrestrial, burrowing, or sub-aquatic, reaching a length of six feet. Teeth pleurodont. No dermal ossifications. Temporal and orbital arches complete. Spines of vertebrae sometimes elongate. A parietal foramen. Zygosphenes sometimes present. Herbivorous and insectivorous.
About three hundred species and fifty genera are known of this family, almost exclusively American in distribution, including our largest and some of our most common lizards,—the Basilisc lizards. Iguanas, "Horned Toads," etc. The large Galapagos lizard, Amblyrhynchus, is a noteworthy herbivorous, aquatic form that seeks its food in shallow water, returning to the land for safety when pressed by enemies; perhaps one of the ways in which terrestrial reptiles acquired water habits.
Eocene. Iguanavus Marsh, North America. Proiguana Filhol, France.
Family Anguinidae. With well-developed, pentadactyl limbs, or limbs vestigial. Body covered with dermal ossicles beneath corneous scales. Temporal opening roofed over by dermal bones. Teeth pleurodont. A parietal foramen.
This family, common to Europe and America, comprises about fifty species. Most noteworthy are the "Glass Snakes" and the "Slow Worms," with vestigial limbs or wholly without them.
Miocene. Anguis, Diploglossus, France.
Family Helodermatidae. Poisonous, terrestrial lizards with grooved, slender, pleurodont teeth. A postorbital but no temporal arch, the squamosal absent; prefrontal and postfronto-orbital in contact over orbits. Parietals and frontals fused. No parietal foramen. Upper surface of body and skull more or less covered by dermal ossicles. An ossified, subfrontal, rhinencephalic chamber. Quadrupedal.
But one genus and two species of this family are known, the fa-
