Newman (_op. cit._:134-35) mentioned that in small sandy areas nests were frequently in contact and overlapped; he found one nest containing nine small eggs contiguous with 23 large eggs. Breckenridge (1944:187) reported a nest of 56 eggs of two slightly differing sizes, and probably from two females. Evermann and Clark (1920:594) discovered "probably 10 or 12 nests in a distance of a few yards" and mentioned one nest containing 25 eggs "that evidently belonged to two different sets ... In the bottom were 10 eggs that looked old ... and ... separated from them by sand, were 15 other eggs." Nesting sites of _muticus_ were mentioned by Muller (1921:181) on one of several small islands having "gently sloping sand and mud shores, and interior areas of open sand and densely growing willows" in the Mississippi River, near Fairport, Iowa. The same author wrote that the egg-laying season is from late June to early July, and that the female selected a place 10 to 60 feet inland "with an unobstructed view of the open water." Farther north on the Mississippi River near Dubuque, Iowa, Goldsmith (1945:447) found that _muticus_ preferred "clean, somewhat level sandbars and sandy shores free from trash, weeds ... and exposed to open view." The same species, however, may "make unsatisfactory nests ... in any place they can find sand, even in the weeds and bushes ... when the river is high, covering the sandy plots ..." Sometimes nests, which were "seldom nearer than six feet or more than twenty-five feet from water ...," were submerged by a rise in water level. In Missouri, Hurter (1911:251) found that individuals of _muticus_ came "... out on the sandbars in the Mississippi River to deposit their eggs ... At the end of May up to the middle of June ..." Cahn (1937:182) wrote that the nesting season of _muticus_ is early July near Meredosia, Illinois. Anderson (1958:212, Fig. 1) found nests of _muticus_ along the Pearl River in Louisiana on an open sandbar (not in gravel, fine sand or silt), whereas nests of _Graptemys_ were confined to the landward margin of the sandbar. The onset and length of the breeding season seems to be geared to the climatic conditions under which the species occurs, and, as would be expected, begins earlier and lasts longer in southern latitudes than in northern latitudes. The period of deposition of eggs in _T. ferox_ (Florida) is from late March to mid-July, whereas that of northern populations of _spinifer_ and _muticus_ (southern Great Lakes region) is usually from mid-June to mid-July.