Ventricle pumps mixed blood (oxygenated and deoxygenated) in

Calotes (Reptilia) has a 3 chambered heart with incompletely divided septa. Oxygenated and deoxygenated blood mix up in the ventricle. In birds and mammals, a four-chambered heart is present and so they exhibit complete double circulation. There no mixture of oxygenated and deoxygenated blood. The right ventricle pumps deoxygenated blood while the left ventricle pumps oxygenated blood.Corvus and Columba are birds. Pteropus is a mammal.