Key to Species of Tympallopatrum

1. Elytra with straight costae and lacking callosities; metasternum with midlongitudinal sulcus ............................................................................................. longitudum Perkins

­ Elytra with arcuate or sinuate costae, and with callosities, at least at summit of posterior declivity; metasternum with midlongitudinal sulcus or median oval fovea........... 2

2. Callosity at summit of posterior declivity of each elytron continued in sinuate costa to margin of elytron; metasternum with median oval fovea ................ curvicostum n. sp.

­ Callosity at summit of posterior declivity of each elytron not continued posteriorly in costa, or with costa short, straight, and not attaining elytral margin............................. 3

3. Callosities large, each elytron with callosity on disc near midlength; metasternum with midlongitudinal sulcus; dorsum piceous with brown setae .................. callosum n. sp.

­ Callosities small, no callosity on disc near midlength; metasternum with median oval fovea; dorsum brown with yellow maculae and golden­yellow setae. aureolum n. sp.