r, Chicago Natural History Museum
(CNHM). Pete S. Chrapliwy, John K. Greer, Robert G. Webb, and Kenneth
L. Williams all contributed field data concerning the specimens of
_P. s. taylori_ that they collected. I am especially grateful to Webb
for donating two specimens to the University of Utah (UU). Special
gratitude is expressed to Wendell L. Minckley and Robert B. Wimmer
for assistance with field work at Cuatro Cienegas. Daniel Rodriguez,
Cuatro Cienegas, guided us to the various ponds at and near the type
locality. Robert R. Miller, Robert G. Webb, and Donald Tinkle read the
manuscript and offered helpful criticisms. Figures 1 and 2 were drawn
by Lorna Cordonnier.

_Comparative materials examined_ (total of 135 specimens).--_P. s.
elegans_ (52 specimens): KU 2897-8, 3195, 18337, 18341, 18345, 18347,
18364, 45027-31, 45033, 46750, 46863, and John M. Legler 1394 and
1435, various localities, Kansas; KU 16400, Howard Co., Texas; KU
39983-4, 8 mi. N and 2 mi. W Piedras Negras, Coahuila; KU 33525,
33527-9, La Gacha, Coahuila; CNHM 28843-5, 55625-45, Rancho las
Ruscias, Muzquiz, Coahuila; KU 39982, 2 mi. S and 3 mi. E San Juan de
Sabinas, Coahuila; KU 33524, Don Martin Reservoir, Coahuila; _P. s.
elegans_ x _taylori_ (3): KU 53785-7, 8 mi. W. Nadadores, Coahuila;
_P. s. gaigeae_ (39): MCZ 54724, Elephant Butte Reservoir [Sierra or
Socorro Co.], New Mexico; KU 51158-61, 51202-3, Lajitas, Brewster Co.,
Texas; KU 51162-6, 51204-6, 51315, 1 mi. NW Ojinaga, Chihuahua; KU
33884, 51167-72, 51207-20, 3 mi. N and 5 mi. E Meoqui, Chihuahua; IU
43583-4, La Cruz, Chihuahua; _P. s. ornata_ (9): MCZ 46392-3, Rio
Purificacion, Rancho Sta. Ana, Tamaulipas; MCZ 46397, E of Gueemez,
Tamaulipas; MCZ 46400, Jimenez, Tamaulipas; KU 40161-2, Alvarado,
Veracruz; KU 40131, San Andres Tuxtla, Veracruz; V. E. Thatcher 98, 15
mi. N Teapa, Tabasco; KU 40139, Cantemo[c], Tabasco; _P. s. taylori_
(23 in addition to type series): KU 51438, 51442, 53788-53801
topotypes; KU 53802-5, 8.5 mi. SW Cuatro Cienegas, Coahuila; KU
51439-41, 10 km. S Cuatro Cienegas, Coahuila; _P. floridana texana_
(10 from Coahuila): KU 39985, 2 mi. W Jimenez; CNHM 55654, Allende;
CNHM 55646, Cd. San Juan; CNHM 55648, Hermanas; CNHM 55649-53,
Lampacitas; KU 33526, Don Martin Reservoir.

LITERATURE CITED

CARR, A.
1952. Handbook of turtles: the turtles of the United States,
Canada, and Baja California. Cornell Univ. Press,