The locomotion of the marsupial, Antechinomys spenceri and the rodent, Notomys cervinus was studied by recording their tracks on long strips of smoked kymograph paper and by means of slow‐motion cinematography. Although both animals occupy the same habitat and are similar in their general appearance, their methods of locomotion differ greatly, since Antechinomys leaps quadrupedally, while Notomys leaps bipedally at fast speeds and runs quadrupedally at slower speeds. The mean speed of both genera was 2.7 m/sec but the mean length of stride of Notomys was 51.2 cm compared with 44.3 cm in Antechinomys. The locomotion of the two Australian genera is compared with that of the North American rodents, Dipodomys and Microdipodops. The significance of the different types of locomotion is discussed. Copyright © 1969, Wiley Blackwell. All rights reserved
