[1] Nominative plural, perhaps quoted from somewhere, or else simply generated by the accusative plural in the quotation which follows. LSJ s.v. deem this a word of dubious sense (web address 1) but suggest nevertheless, very plausibly, that it may be a variant of ἐπηγκενίδες , which occurs in the dative plural in Homer, Odyssey 5.253; LSJ translate the word there as "long planks bolted to the upright ribs of the ship", and Casson (46 n.19, 151 n.49, 218 n.5, 392) more succinctly as "gunwales".
[2] Agathias 5.21.