Type species: Grapsus huzardi Desmarest, 1825, by present designation
Etymology: The name Guinearma is composed of two parts: Guinea is derived from the Gulf of Guinea, the main distribution area of the genus and -arma has become a typical ending for new genera in the family Sesarmidae, making reference to the type genus Sesarma. Gender neuter.
This genus includes three species as follows (the synonym (after =) and original combinations [in square brackets] are adopted from Ng et al., 2008):
• Guinearma alberti (Rathbun, 1921) comb. nov. [Sesarma (Chiromantes)]
• Guinearma huzardi (Desmarest, 1825) comb. nov. [Grapsus] = Sesarma africana H. Milne Edwards, 1837
• Guinearma kamermani (De Man, 1883) comb. nov. [Sesarma (Chiromantes]