We describe the following 8 new genera and 23 new species of Neotropical Exosternini. Conocassis gen. n. (Conocassis minor sp. n. [type species], Conocassis dromedaria sp. n., Conocassis trisulcata sp. n., and Conocassis invaginata sp. n.), Enkyosoma gen. n. (Enkyosoma rockwelli sp. n.), Pluricosta gen. n. (Pluricosta onthophiloides sp. n.), Pyxister gen. n. (Pyxister devorator sp. n. [type species] and Pyxister labralis sp. n.), Chapischema gen. n. (Chapischema doppelganger sp. n.), Scaptorus gen. n. (Scaptorus pyramus sp. n.), Lacrimorpha gen. n. (Lacrimorpha glabra sp. n. [type species], Lacrimorpha balbina sp. n., Lacrimorpha subdepressa sp. n., and Lacrimorpha acuminata sp. n.), Crenulister gen. n. (Crenulister grossus sp. n. [type species], Crenulister explanatus sp. n., Crenulister dentatus sp. n., Crenulister impar sp. n., Crenulister umbrosus sp. n., Crenulister simplex sp. n., Crenulister paucitans sp. n., Crenulister spinipes sp. n., and Crenulister seriatus sp. n.) These all represent highly distinctive and phylogenetically isolated forms, almost invariably known from very few specimens. All but one species have been collected only by passive flight intercept traps, and nothing significant is known about the biology of any of them.