--+------------+----------
_G. polyphemus_ | (6) |(13) |(13) |
(Florida) |.94 |.53 |.39 |
|(.92-.97) |(.48-.58) |(.36-.42) |
---------------------+-----------+-----------+------------+----------
_G. polyphemus_ |(2) |(2) |(2) |
(Mississippi) |.87 |.53 |.43 |
|(.84-.89) |(.52-.54) |(.40-.45) |
---------------------+-----------+-----------+------------+----------
_G. berlandieri_ |(21) |(22) |(21) |
(Texas and NE Mexico)|.78 |.56 |.46 |
|(.70-.83) |(.48-.62) |(.43-.51) |
---------------------+-----------+-----------+------------+----------
_G. agassizii_ |(6) |(8) |(8) |
(U.S. and N. Sonora) |.77 |.53 |.41 |(.38-.44) |
|(.70-.83) |(.49-.58) | |
---------------------+-----------+-----------+------------+----------
_G. agassizii_ | |(4) |(4) |(4)
(Alamos, Sonora) | |.56 |.39 |.92
| |(.52-.59) |(.37-.41) |(.87-1.00)
---------------------+-----------+-----------+------------+----------
_G. flavomarginatus_ |(2) |(3) |(3) |(3)
(North-central | | | |
Mexico) |.83 |.54 |.43 |.71
|(.82-.83) |(.51-.58) |(.42-.44) |(.58-.78)
---------------------+-----------+-----------+------------+----------

Thus far, _G. flavomarginatus_ is known only from the three
localities represented in the type series and from the indefinite
locality, "Bolson de Mapimi", Chihuahua, given by Duges
(1888:146-7, and 1896:479). These long-doubted references of
Duges to _Gopherus polyphemus_ seem clearly to represent _G.
flavomarginatus_, which probably occurs in several or all of the
internally drained basins in northeastern Chihuahua, western
Coahuila, and northern Durango. This region is within the Basin and
Range physiographic province of Fenneman (1931:326-8) and the
Mapimi biotic province of Smith (1949:231). Duges (_supra cit._)
seems to have used "Bolson de Mapimi" in a restricted sense, as it
is shown on some recent maps (Nat. Geog. Soc., Map of