New genera of philopotine spider flies (Diptera, Acroceridae) with a key to living and fossil genera.

Information on the three previously described species of Halocoryza Alluaud is updated and a new species for the genus from Isla Carmen, Sea of Cortés, Baja California Sur, México is described. Halocoryza whiteheadianasp. n. was found at UV light on a beach of that island. This species does not fit the profile of the other three species, i.e., living on coralline beach sands, or in the Mangrove intertidal zone. Two alternative possibilities as to why this is so are suggested and a study plan for testing these possibilities is proposed.