This entry in the Catalogue comes immediately after the Rhodian contingent under Tlepolemos, and immediately before Achilles' Myrmidons. None of the three leaders appears elsewhere, nor are any of their relatives mentioned elsewhere, with the exception, of course, of Herakles, grandfather of Pheidippos and Antiphos. Of the islands over which they rule, only Kos is mentioned again.
There can be no reason to doubt the identification of Syme, Nisyros, Krapathos, and Kasos, with the islands which still bear those names, apart from a slight and normal change in the case of Krapathos—Karpathos. By Κῶς Εὐρυπύλοιο πόλις is presumably meant a city on the site of the present Kos-town, called elsewhere Μερόπις. Thus the Delian Hymn to Apollo refers to Kos as πόλις Μερόπων ἀνθρώπων. This is borne out by the other references to Kos in the Iliad, for there it is given the epithet εὖ ναιομένην, which elsewhere seems to be applied to cities.
The problem of what Homer meant by νῆσοι Καλύδναι was already being discussed in Strabo's time. He says that the general opinion (φασί) was that νῆσοι Καλύδναι meant Kalymna and the islands near by, Kalymna perhaps being once called Καλύδνα, but that some said that Leros and Kalymna were meant, while Demetrios of Skepsis held that Καλύδναι was a plural similar to Ἀθῆναι or Θῆβαι. While there does not seem to be any good evidence that Kalymna (= Kalymnos) was alone ever called Καλύδνα or Καλύδναι, there is no doubt that the people of Kalymna and the adjacent islands—presumably Telendos and Pserimos, and possibly also Kalolimnos—were called Καλύδνιοι in the fifth century B.C.