trachystomata

‖n. pl. [ NL., fr. Gr. &unr_; rough + stoma. ] (Zool.) An order of tailed aquatic amphibians, including Siren and Pseudobranchus. They have anterior legs only, are eel-like in form, and have no teeth except a small patch on the palate. The external gills are persistent through life. [ 1913 Webster ]