ABSTRACT Axiorygmanethertoni is described from material collected in about 30 m of water off the Key Largo area of the Florida Keys, and from 52-58 m in the Gulf of Mexico off the west coast of Florida. The genus is characterized by the possession of sexually dimorphic chelipeds, and by the absence of an appendix masculina in the male. The species burrows in sand flat areas around coral heads, with densities of up to 80/m2. The burrows, usually about 15 cm long, are often blocked by debris such as calcareous algal fragments. The species is considered to play an important role in the transfer of material across the sediment-water interface.