THOMPSON: Humboldtiana from Chihuahua and Texas
Figs. 1-7. Humboldtiana presidii Pilsbry, 1939.. Figs. 1-4: Texas, Presidio Co., San Carlos Tunnel, 2.5 miles N of Coal Mine Ranch House (UF 354500). Figs. 5-7: Holotype, USNM 134160.