Second Aorist Subjunctive.—All the forms of the 2 aor. subj. are due to contraction of the thematic vowel with the weak stem-vowel. Thus θῶ, etc., from θέω, θέῃς, θέῃ, θέωμεν, etc.; ὧ, etc., from ἕω, ἕῃς, ἕωσι; δῶ, etc., from δόω, δόῃς, δόῃ; στῶ, etc., from στέω, στέῃς, etc., with ε from η before a vowel. Cp. cross682.
a. ἐπριάμην has πρίωμαι with ώη in place of the final vowel of the stem ( cross749 b).
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].