Abstract: Soft appendages are common in fishes, particularly on the head and along the lateral line. Excluding modified fin rays, these appendages are generally classified as barbels or cirri. Though barbels are mainly associated with Siluriformes, they have evolved in several lineages of fishes. The structure and uses of barbels have been explored, and here we document variation in morphology of cirri. We surveyed eight species of fishes, seven with cirri, and one with barbels (an agonid), to better characterize the differences between the two morphologies. We used histology and scanning electron microscopy and found that cirri in Blepsias have taste buds, and share near-identical internal structure to agonid appendages. As the functions of barbels and cirri are highly variable, structure is a better way to differentiate them. Siluriform barbels share an intrinsic musculature which cirri lack. We propose to define a cirrus as any soft appendage with a fibrous core and no intrinsic musculature, while a barbel has intrinsic musculature. Since agonid appendages lack musculature they are more properly called cirri. Other fishes that have also been mischaracterized as having barbels, include Acipenseriformes, artedidracoids, cyprinids, gadids, osteoglossids, and triportheids. These all have cirri rather than barbels.