Vertebral centra are amphicoelous. Ribs are bicapitate. Spinal-nerve foramina are absent from all vertebrae. Anterior glomeruli of the kidney are reduced or absent. Reproductive characters Fertilization is internal.
Ciliated epithelium is absent from the cloacal tube and anterior cloacal chamber of females.
Epidermal lining is present in the anterior cloacal chamber of females. Evaginations are absent from the dorsolateral walls of the male cloacal tube. Anterior ventral glands are present in the cloacae of females. Spermathecae are present in the female cloacal chamber. Glands secreting into the dorsal walls of the female cloaca are absent.