Ornate box turtles basked chiefly between sunrise and 10 or 11 A. M. Body temperatures of 60 basking turtles ranged from 17.3 to 31.4 degrees (mean, 25.5 ± 3.08[sigma]). More than two-thirds (42) of these body temperatures were higher than the air temperature near the turtle, indicating probably that body temperature rises rapidly once basking is begun. In the instances where body temperature was below air temperature, the turtles had recently begun to bask (many were known to have just emerged from forms or other cover where they had spent the night) or were warming up more slowly because of reduced sunlight. On cloudy days basking began later than on clear days and body temperatures usually remained at a suboptimum level. Turtles that basked on days that were cloudy and windy, or cold and windy, did so in sheltered places, usually on the leeward sides of windbreaks such as limestone rocks, rock fences, or ravine banks. It was evident in these instances that the turtles either sought such shelter from the wind or remained ensconced in the more complete shelter of a form or burrow, not emerging at all. Open areas of various kinds were used as basking sites. Level ground--such as on roads, cattle pathways, and bare areas surrounding farm ponds--having unobstructed morning sunlight, nearby dense vegetation, and choice opportunities for feeding (cow dung, mulberry trees) was preferred. Basking was frequently combined with feeding; in several instances box turtles were noted early in the morning at suboptimum body temperatures eating grasshoppers, berries, or dung insects. The predilection of box turtles for open areas is probably important in permitting extended activity at suboptimum temperatures. _T. ornata_ probably carries on more nearly normal activity on cool days than do reptilian species with more sharply delimited thermal tolerances. Collared lizards (_Crotaphytus collaris_), for example, are chiefly inactive on days when the sky is overcast, although a few individuals having suboptimum body temperatures can be found in open situations (Fitch, 1956a:229 and 1956b:442). [Illustration: FIG. 22. The relationship of body temperature (Centigrade) and kind of activity in _T. o. ornata_, compiled from 355 field observations. Vertical and horizontal lines represent, respectively, the range and mean. Open and solid rectangles represent one standard deviation and two standard errors of the mean, respectively.] Toleration of Thermal Maxima and Minima The foregoing remarks on basking indicate the approximate, normal, thermal tolerances of ornate box turtles. Many additional records of body temperature were taken from turtles that were found under cover. Turtles under cover in daylight were usually seeking protection from either below-optimum or above-optimum temperatures. In avoiding low temperatures, turtles usually chose more complete and permanent cover than in avoiding high temperatures.