Herbert Weir Smyth, A Greek Grammar for Colleges

a. <*> when they have a long penult and an active meaning: στρατ-ηγός general.

b. <*> when they have short penult and an active meaning: πατροκτ<*> <*>icide, λιθο-βόλος throwing-stones, λαιμο-τόμος throat-cutting, ὑδροφο<*> <*>ter-carrier.

c. propar<*>, when they have a short penult and passive meaning: πατρόκτο<*> <*>ain by a father, λιθό-βολος pelted with stones, λαιμό-τομος with thr<*> out, αὐτό-γραφος written with one's own hand.

N.—A<*> compounds of -οχος (ἔχ-ω, 878), -αρχος (ἄρχ-ω), -συ_λος (συ_λά-ω rob<*> -πο<*> (πέρθ-ω destroy) are proparoxytone; ἡνί-οχος (rein-holder) charioteer, <*> commander of horses, ἱερό-συ_λος temple-robber, πτολί-πορθος sacking cities. <*> staff-bearer (ῥαβδός) is contracted from ῥαβδό-οχος.