legans_. I regard _P. s. gaigeae_ as a subspecies of the
upper Rio Grande and disrupted parts of that drainage; the range of
that subspecies meets that of _P. s. elegans_ somewhere between the
Big Bend region and Piedras Negras. In any event, the influence of
_gaigeae_ is not so widespread as other authors (Carr, _loc. cit._;
Hamilton, _loc. cit._; Hartweg, 1939:3-4) have indicated.

Further collecting in the Rio Salado and its tributaries east and
north of Cuatro Cienegas will be necessary before the exact range of
_P. s. taylori_ can be determined.

_Variation._--Characteristics ascribed to the holotype pertain in
general to all specimens in the hypodigm, except as noted below. The
postorbital mark is in contact with the eye on one or both sides in 46
per cent of the specimens (narrowly separated from eye in remainder)
and is in contact with a neck stripe (on one or both sides) in 35 per
cent of the specimens. The pattern of the antebrachium is as shown in
Fig. 2 in all specimens except that the thin lateral stripe is
obliterated by melanism in older specimens of both sexes. The lateral
edges of the posterior plastral lobe are reflected downward, at least
slightly, in all but one specimen (an adult, kyphotic female). The
first central lamina is straight-sided in juveniles and becomes
urn-shaped only in adults. The relative height of the shell tends to
increase with a general increase in size in both sexes.

[Illustration: FIG. 1. _Pseudemys scripta taylori_ new
subspecies: left side of head, female paratype (KU 46933),
x 1.]

[Illustration: FIG. 2. _Pseudemys scripta taylori_ new
subspecies: anterior view of left antebrachium, female
paratype (KU 46934), x 1.]

_Comparisons._--Of the five other subspecies of Mexican _P. scripta_
mentioned above, three subspecies (_gaigeae_, _hiltoni_, and
_nebulosa_) form a natural group herein referred to as the _gaigeae_
group. _Pseudemys s. taylori_ is distinguished from members of the
_gaigeae_ group by elongate, red postorbital mark (yellow or orange in
the _gaigeae_ group), extensive black plastral pattern (narrow--or if
wide, brownish--in _gaigeae_ group), and serrate lower jaw (nearly
smooth in _gaigeae_ group).

The subspecies _P. scripta taylori_ differs from _P. scripta elegans_
as indicated in the following comparative list of characteristics:

_P. s. taylori_ _P. s. elegans_

1. Extensive black plastral