Electron microscopy has been used to identify isolated chemosensory cells scattered in the oral epithelium and in the external epidermis of four teleosts. These cells are regarded as chemosensory because they closely resemble the gustatory cells of the taste buds in each species. Nerve fibres are associated with the bases of the scattered chemosensory cells, but synaptic modifications have not been found. Since such cells are found on the head and body of fish without external taste buds, it is assumed that on the body they are innervated from spinal nerves and hence belong to the common chemical sense.