Page:The Osteology of the Reptiles.pdf/202

184 centrale is usually retained in later reptiles, but the fifth tarsale is absent in all reptiles since Triassic times, and a free centrale is absent in all living reptiles, though present in most mammals.

. 151. Limbs: A, Trematops (Temnospondyli). One half natural size. B, Eosauravus (Cotylosauria). About twice natural size.

. 152. Ophiacodon (Theromorpha): right hind leg, from mounted skeleton. A little less than one third natural size, a, astragalus; c, calcaneum.