The distribution of nerve fibers in the osseous spiral lamina was examined in whole mount preparations of the cochleae of three species of bats which emit pulses containing both frequency‐modulated (FM) and constant‐frequency (CF) components:Pteronotus p. parnellii, Hipposideros diadema, andRhinolophus ferrum‐equinum. InPteronotusthe nerve‐fiber population was extremely dense at the beginning and end of the large basal coil and relatively sparse between these areas. The striking contrast in nerve‐fiber density seen inPteronotus(family Mormoopidae) was not seen in the other two “CF/FM” bats (family Rhinolophidae).