Barnes described two groupes of Maevia salticids: five eastern species, best characterized by Maevia inclemens (and the only widespread representative of the genus), and one southwestern species Maevia poultani. The latter species has been recorded in Arizona and Texas as well as in Tamaulipas, Mexico. The male M. poultani is distinct. The posterior area of the male’s carapace has a large, contrasting gray area shaped a bit like a crab (manta ray?). Although I have not conducted time trials the movements of the two males I have observed seemed extremely quick.
Barnes, 1955