Lewisville is situated in the drainage basin of the Red River and is approximately eight miles east of the Red River and 30 miles west of the westernmost tributary of the Ouachita River drainage. _T. s. pallidus_ occurs in the Red River drainage; _hartwegi_ occurs in the Ouachita River drainage. Perhaps there is intergradation between _pallidus_ and _hartwegi_ in the intervening streams. There is no data to indicate from which river or stream each specimen obtained by McEntyre came; one would presume that all specimens came from the Red River drainage. But this is not certain. Certainly the 47 specimens designated herein as _pallidus_ came from the Red River drainage. I suspect that KU 2944, 2963 and 2964 were obtained from tributaries of the Ouachita River drainage. _T. s. pallidus_ intergrades with the _spinifer-hartwegi_ population where the Red River joins the Mississippi River in the lower Mississippi Valley in Louisiana. The majority of 13 juvenal specimens from the Red River near Shaw, Concordia Parish, Louisiana (USNM 99862-69, 99871-75), resemble _pallidus_ in having inconspicuous white tubercles on a pale brown carapace. The white tubercles are conspicuous in USNM 99871. Some specimens have a few small dark dots confined to the margin of the carapace, as do some "variant" individuals from well within the geographic range of _pallidus_. USNM 99865 is referred to _hartwegi_ because the carapace is covered with dark ocelli approximately one millimeter in diameter. Some specimens from farther west in the Red River drainage are referred to _hartwegi_. One (USNM 100420) of three from Natchitoches Parish, Louisiana (TU 5763, USNM 100420-21), having blackish dots on the carapace, is applicable to _hartwegi_. Of two turtles from Grant Parish, Louisiana (TU 5647, 12735), only 12735 has dark dots and ocelli (_hartwegi_). One specimen from Rapides Parish, Louisiana (TU 14040), having dark dots on the entire surface of the carapace, is referred to _hartwegi_.