Figures 1–12. Characteristics of the head, sternum and elytra of Stenaspis. 1–3) S. veritcalis, male, Puebla, MEX. 4–6) S. verticalis, female, Jalisco, MEX. 7, 10) S. castaneipennis, male, Oaxaca, MEX. 8, 11) S. solitaria, male Cochise Co., AZ, USA). 9, 12) S. verticalis, male, Nuevo Leon, MEX. 1–6) Characteristics of the head, i.e "frons large, square, perpendicular, abruptly separated from anteocular space," 1, 4) Gena large, quadrate; mandibles well separated from lower eye lobe. 2: 2a; 5: 5a) Dorsal anterior margins of genae ridged. 2: 2b; 5: 5b) Frons perpendicular to vertex and recessed between "anteocular space" (i.e., recessed between the dorsal anterior margins of genae). 3, 6) Apex of mandibles acute, simple. 7–9: 7a, 8a, 9a) Prosternal intercoxal process with apex protuberant, ridged between coxae, abruptly declivous behind. 7–9: 7b, 8b, 9b) Mesosternum not protuberant, level with coxae. 10–12) Elytra with apices unarmed.