Kasa ni aina za makobe wakubwa kiasi wanaoishi baharini. Hutaga mayai yao katika mchanga wa fuko za kanda za tropiki na nusutropiki. Kama makobe wote kiwiliwili cha kasa kimefunikwa kwa gamba gumu liitwalo galili, lakini hawawezi kuvuta kichwa na miguu ndani ya galili. Familia Cheloniidae Caretta caretta, Kasa Mtumbi, dufi au duvi (Loggerhead sea turtle) Chelonia mydas, Kasa Uziwa (Green sea turtle) Eretmochelys imbricata, Kasa Mwamba au ng'amba (Hawksbill sea turtle) Lepidochelys kempii, Kasa wa Kemp (Kemp's ridley sea turtle) Lepidochelys olivacea, Kasa Kikoshi (Olive ridley sea turtle) Natator depressus, Kasa Mgongo-bapa (Flatback sea turtle) Familia Dermochelyidae Dermochelys coriacea, Kasa Ngozi (Leatherback sea turtle) Kasa mtumbi Kasa uziwa Kasa wa Kemp Kasa kikoshi Kasa mgongo-bapa Kasa ngozi