NEVADA: _Clark_: observed just north of Black Canyon (Cowles and Bogert, _loc. cit._); Colorado River, 6 mi. N California line (Linsdale, 1940:255). NEW MEXICO: _Chaves_: Bitter Lakes Wildlife Refuge, 12 mi. NE Roswell (Bundy, 1951:314). _Dona Ana_: Río Grande near Mesilla Dam (Little and Keller, 1937:221). TEXAS: _Brewster_: Río Grande at Castolon (Minton, 1959:38). _Val Verde_: mouth of Devil's River (Brown, 1950:250). BAJA CALIFORNIA: Colorado River delta, 7 mi. E Cerro Prieto; Imperial Irrigation District, Alamo Canal, 15 mi. S Internat'l Boundary and Salfatana Canal, 1 mi. N Black Butte (Linsdale and Gressitt, 1937:222). COAHUILA: San Juan (Schmidt and Owens, 1944:103). Hitherto, soft-shelled turtles of the species _Trionyx spinifer_ from the southern and southwestern United States having a pattern of white dots on the carapace have been relegated to the subspecies _emoryi_, but my examination of soft-shelled turtles from Texas has indicated that _T. s. emoryi_ as previously conceived, is a composite of three subspecies. It is necessary, therefore, to recognize two new subspecies. =Trionyx spinifer guadalupensis= new subspecies Guadalupe Spiny Softshell Plates 41 and 42 _Holotype._--UMMZ 89926, alcoholic adult male; obtained 15 miles northeast Tilden, McMullen County, Texas (Pl. 41, bottom, left). _Paratypes._--Forty-two specimens: ANSP 16717 (hatchling), no data; USNM 78515-16 (hatchlings), Colleto Creek, Victoria County, Texas; TU 10143-45, 10148, 10150-59, 10161-65 (adult males), TU 10176, 10833 (immature males), TU 10147, 10149, 10155 (immature females), TU 10160 (adult female), Guadalupe River, 9 miles southeast Kerrville, Kerr County, Texas; UMMZ 89915-21, 89924-27 (adult males), UMMZ 89922-23 (immature females), same locality as holotype; UMMZ 92752 (immature female), San Antonio River, 3 miles west-northwest Goliad, Victoria County, Texas.