Genus Atyoida Randall, 1840

Body pigmented, eyes well developed; short rostrum, dorsal carina typically unarmed, 0-4 ventral teeth; anterior margin of carapace armed with antennal spine, pterygostomian margin sharply or bluntly acute; supraorbital spines absent; telson with setigerous posterior margin overreaching posterolateral angles; 3rd maxilliped with uncinate terminal spine; pereopods without exopods; 1st and 2nd pereopods with chelae heteromorphic (with or without palm), fingers tipped with brushes of setae, carpus of both appendages excavate distally, 3rd pereopod without meral spur in large males; 1st pleopod of male with endopod tapering sinuously but rather regularly to slender apex; 2nd pleopod of male with appendix masculina subcylindrical, spinose over more than distal half.