 The editors of the "Encyclopædia Britannica Eleventh Edition", citing Pliny iii.110, place the tribe's northern limit at the Tessinnus (another unidentified hydronym).The "Ager Praetutianus" is mentioned by Livy and Polybius, as well as by Pliny, as a well-known district, and Ptolemy even distinguishes it altogether from Picenum, in which, however, it was certainly generally comprised.