Historically, since the 18th century and even in the 20th century, the genus name "Bulla" has been used for a great number of bubble-shelled species that belonged to the order Cephalapsidea. From the mid-20th century, authors began to restrict species to the genus "Bulla" in its current meaning. But misidentifications were still numerous through high levels of intraspecific variability in the shell, radula and male genital system. The monograph by Malaquias & Reid (2008) has offered a systematic revision of this genus and has brought order in this genus