Stephanos of Byzantium - Ethnika
Kaspeiros: a city of the Parthians situated on the border with India. Herodotus, book 3. The ethnonym is 'Kaspeiroi', as per Dionysios in book 3 of his Bassarika: 'and among them the far-famed Kaspeiroi, and the Arienoi.' And again: 'a Kossaian by descent, from Kaspeiros, who, out of all the Indians that exist have the swiftest knees; for as much as lions excel in the mountains, or as much as dolphins within the resounding sea, as the eagle stands out among the birds that flock together, and as horses dashing across the flat plain, so much do the Kaspeiroi surpass with the lightest feet, among the tribes who the undying Dawn takes as her charge.” As it is 'Stageirites' from 'Stageiros', it should therefore be 'Kaspeirites' from 'Kaspeiros'. But barbarians do not observe Greek analogy.
Stephanos excerpt (left) is aligned with matched Herodian passages (right). Colors indicate corresponding overlap spans.
Κάσπειρος, πόλις Πάρθων προσεχὴς τῇ Ἰνδικῇ. Ἡρόδοτος γʹ. τὸ ἐθνικὸν Κάσπειροι, ὡς Διονύσιος ἐν γʹ Βασσαρικῶν “ἐν δέ τε Κάσπειροι ποσσικλυτοί, ἐν δ´ Ἀριηνοί”. καὶ πάλιν Κοσσαῖος γενεὴν Κασπειρόθεν, οἵ ῥά τε πάντων Ἰνδῶν ὅσσοι ἔασιν ἀφάρτερα γούνατ´ ἔχουσιν· ὅσσον…
…νῶ ὄνειρος, πέπτω πέπειρος. τὸ δὲ 'αι' τῆς πρώτης συλλαβῆς γέγονεν ἀπὸ τοῦ ἀΐσσω κατὰ κρᾶσιν. ἔστι δὲ καὶ Αἴγειρος πόλις Μεγαρίδος, ὡς Θεόπομπος πεντηκοστῇ ἕκτῃ, ἣν Στράβων Αἰγείρουσαν λέγει. σάπφειρος λίθος, Στάγειρος. Κάσπειρος πόλις Πάρθων προσεχὴς τῇ Ἰνδικῇ καὶ τὸ ἐθνικὸν ὁμοφώνως. Στάλιρος, Σίτιρος, Βίστιρος πόλις Θρᾴκης καὶ Πίστιρος τὸ ἐμπόριον. Κύστιρος, Δύσιρος, Βεδύσιρος, ἄϊρος σύνθετον ἀπὸ δισυλλάβου Ἶρος «ἦ τάχα Ἶρος ἄϊρος