SYNOPSISThe histology of the preputial skin and its appendages is described in the two African rhinoceros formsCeratotheriumandDiceros. Apocrine sweat glands occur in both. A feature of theCeratotheriumpenis is the presence of distinctive surface papillae which are the mouths of eccrine sweat glands whose secretory tubules are embedded in a mass of subepidermal lymphoid tissue, an arrangement hitherto unrecorded for any mammal.