----------------+---------+---------+---------+----------+--------+---------+-------+--------+---------+-------+-------+-------------- The American _Eumeces laticeps_ and _E. inexpectatus_ seem to be more specialized than _E. fasciatus_ and might have been derived from it or from a common ancestor differing but little from the modern _fasciatus_. Both differ from _fasciatus_ in having more scale rows. _E. laticeps_ also differs in having eight instead of seven supralabials and in having the median subcaudal scales greatly widened, in having intercalated plates on the outer side of the fourth toe nearly to the ultimate phalanx, posterior supralabial low and elongate, young sometimes seven-lined instead of five-lined, and especially in much larger size, stocky build, and in early loss of striped pattern. _E. inexpectatus_ differs in having the median subcaudals not at all enlarged, and in having the dorsolateral stripes a little more widely separated from the midline. _Eumeces fasciatus_ and its relatives present a curious exception to Jordan's Rule, which states that the nearest relatives of any given species are to be found neither in the same area nor in a remote one, but in an adjacent region separated by a barrier. _E. fasciatus_ is absent from almost all of Florida; otherwise its range overlaps most of the ranges of both _laticeps_ and _inexpectatus_, the former including the southeastern United States south of about latitude 40°, and the latter being mainly in the Atlantic and Gulf states from Chesapeake Bay into eastern Louisiana. Presumably both of these species began their differentiation as southern populations of an ancestral _fasciatus_ and later became isolated from it and continued their differentiation until they overlapped it again as distinct species. The differentiation of _laticeps_, being much greater, presumably took place at an earlier time than did that of _inexpectatus_, and at present it overlaps _fasciatus_ more extensively. _E. laticeps_ probably diverged to such an extent that competition with _fasciatus_ is greatly reduced where the two species occur together.