Key to the West Atlantic species of the family Ctenochelidae (sensu Poore 1994; De Grave et al. 2009)

1. Rostral spine present; eyestalks with small and poorly pigmented cornea........................................ 2

-. Rostral spine absent; eyestalks with well-developed cornea [major chela with pectinate fingers; third maxilliped without exo- pod]...................................................................... Ctenocheloides almeidai sp. nov.

2. Both major and minor chelae with pectinate fingers.............................................. ( Ctenocheles)...3

-. Major chela fingers not pectinate......................................................................... 4

3. Cheliped ischium and merus armed with large, acute teeth on ventral margin; anterolateral teeth strong, sharp; third maxilliped without exopod...................................................................... Ctenocheles holthuisi

-. Merus and ischium of chelipeds unarmed; anterolateral teeth obtuse; third maxilliped with exopod..... Ctenocheles leviceps

4. Sixth pleomere with sharp lateral projections; third maxilliped without exopod.................... Dawsonius latispina

-. Sixth pleomere without sharp lateral projections; third maxilliped with exopod......................... ( Gourretia)...5

5. Third maxilliped ischium ventrally produced in conspicuous acute tooth; major cheliped ischium armed with large teeth on ventral margin; uropodal exopod without notch.................................................. Gourretia laresi

-. Third maxilliped ischium ventrally bluntly produced; major cheliped ischium somewhat rugose, but without large teeth on ventral margin; uropod with notch........................................................... Gourretia biffari