A small amount of confusion appears in the literature on the cranial myology of Necturus, and the Urodela generally, by the use, among divers anatomists, of the same name for two different muscles. Both of these muscles function as depressors of the lower jaw. On occasion, both muscles have been named digastric, and depressor mandibulae ; and other names have also been used. In order to clarify the use of the terms M. depressor mandibulae and M. branchio-mandibularis, I have inserted tables of the synonymy for these two muscles in the Urodela, with brief descriptions of these muscles in Necturus
