Tracking of opossums suggested that having once left the home den, an animal ordinarily did not return until it had finished its nightly foraging, and wandered more or less at random over its home range. Successive capture sites for any one opossum might be near together or far apart with respect to its over-all range, but on the average, they would be separated by approximately half the breadth of the home range assuming the animal's activity to be evenly distributed over the whole area. Each of twenty-two opossums was caught at only two different trapping stations. For this group, the average distance between stations was 761 feet (657 feet for seven males and 810 feet for 15 females) indicating home ranges of approximately 42 acres in extent. Each of ten opossums was caught at three different stations; for these the distances between the first and second stations, between the first and third and between the second and third comprise three distinct movement records, and the average of all three probably affords a more reliable figure for the radius of the home range than does the single movement available for each of the 22 animals captured at only two stations. For these average individual movements the mean of this whole group of 10 was 841.5 feet. Each of five opossums was taken at 4 different trapping stations, and for each of these a record of six different movements was available. The average was 1016 feet. For the 37 opossums caught at two, three or four different trapping stations, the mean distance was 817 feet; this is an indication of home ranges of approximately 48 acres in extent. Each of thirteen opossums was caught at five or more trapping stations. The distribution of these stations affords a crude idea of the extent and position of each animal's home range, but ordinarily it might be expected that the area included between capture sites would be less than the animal's actual home range, because relatively few of the sites of capture would be on the margin of the home range. For this group, maximum distances between trapping stations averaged 1954 feet suggesting a home range of nearly 70 acres, larger than that computed for the opossums caught at only two, three, or four stations. However, for those caught at five or more stations, the time involved averaged longer and probably some had altered their ranges to invade new areas. Ranges may have been broadly oval rather than circular so that the maximum diameter measured between stations exceeded somewhat the average range diameter for each animal.