Recent collections of the benthic macro- and meiofauna associated with the mesophotic coral ecosystems of Puerto Rico have revealed two new Cumacea from the family Nannastacidae. A new genus Cumellana and two new species, Cumellana caribbica and Cumella alexandrinae are described herein. The new genus Cumellana can be distinguished from the other genera of the family Nannastacidae by having a long antennule and pereopod 2 with short terminal setae, equal in length.