Key to identification of females of the genera of Pterygosomatidae analyzed in this study

1. Companion seta (ft) of tarsus I very reduced, simple and spiniform; hypostome with a rostral flange. Pimeliaphilus Trägårdh

-. Companion seta (ft) of tarsus I long, nude, barbed or peripectinate; hypostome simple.............................. 2

2. Idiosoma oligotrichous or hypertrichous, dorsal idiosomal setae c3 present, coxal setae 4c absent, and genital setae (g1) spine-like nude or acuminate nude and slender, located on the tip of lobes............................... Geckobiella Hirst

-. Idiosoma oligotrichous, dorsal idiosomal setae c3 absent, coxal setae 4c present, and genital setae (g1) arboriform or spine-like serrate, located on the ventral cuticle (not on lobes)......................................................... 3

3. Solenidion ω 1 on tarsus I absent; dorsal idiosomal setae h1 peripectinate and long subequal to h2....................... ..................................................... Bertrandiella Paredes-León, Klompen and Pérez gen. nov.

-. Solenidion ω 1 on tarsus present; dorsal idiosomal setae h1 tuft-shape and very reduced (a quarter of the length of the pectinate setae h2).............................................................. Tequisistlana Hoffmann and Sánchez