Lewis & Short

cammărus (camărus, gammă-rus), i, m., = κάμμαρος, a sea-crab, lobster (so called from its vaulted back), Varr. R. R. 3, 11, 3; Col. 8, 15, 6; 8, 17, 4; Plin. 27, 3, 2, § 9; 31, 8, 44, § 96; Mart. 2, 43; Juv. 5, 84 al.