From Letter ccxxxvii. it would appear that Demosthenes was now in Galatia, where he had summoned a heretical synod.  The Ben. note quotes a law of Valens of the year 373 (Cod. Theod. ix. tit. i. 10):  Ultra provinciæ terminos accusandi licentia non progrediatur.  Opertet enim illic criminum judicia agitari ubi facinus dicatur admissum.  Peregrina autem judicia præsentibus legibus coercemus.