I read that the first proper analysis of the Constantinople synaxarion – list of saints, quick details, and their saints’ day – is that in the Acta Sanctorum by H. Delahaye: Synaxarium ecclesiae Constantinopolitanum e codice Sirmondiano nunc Berolinensi. This is online here. He’s printing a Berlin manuscript, but giving material from other manuscripts.
Here’s the entry he gives for May 19th, column 695, line 35, with a ChatGPT output for it:
2. Τῇ αὐτῇ ἡμέρᾳ ἄθλησις τοῦ ἁγίου μάρτυρος Κολούθου.e Οὗτος ἦν ἐπὶ Μαξιμιανοῦ τοῦ βασιλέως ἐκ Θηβαΐδος τῆς Αἰγύπτου ἐν Ἑρμουπόλει· καὶ διὰ τὴν εἰς Χριστὸν ὁμολογίαν Ἀρριανῷ τῷ ἡγεμόνι προσηχθῇ καὶ μήτε κολακείας δελεασθεὶς μήτε τὰς ἀπειλὰς αὐτοῦ καταπτήξας, πρῶτον μὲν μεγέθει λίθου τὸν αὐχένα βαρύνεται, εἶτα τὴν διὰ πυρὸς λαμβάνει ἀπόφασιν· καὶ ἐν αὐτῷ βληθεὶς τελειοῦται.
On the same day, the contest of the holy martyr Coluthus. This man lived under the emperor Maximian, from the Thebaid of Egypt, in Hermopolis. And because of his confession of Christ, he was brought before the governor Arianus; and, having been neither enticed by flattery nor terrified by his threats, first his neck is weighed down by the weight of a stone; then he receives the sentence by fire; and, having been cast into it, he is perfected (i.e., brought to martyrdom).
I was hoping to give you a proper “Life” of St Colluthus by now, but my local library have let me down. I placed an ILL for a volume before I went away, two weeks ago. This they never acknowledged. I wrote again today, and was ignored. Possibly the staff member is on holiday. Tomorrow I will write to a more general email address and we will see.