Myroconger prolixus n. sp., described from a 383 mm TL specimen trawled in 260-280 m southeast of New Caledonia, and Myroconger nigrodentatus n. sp., described from a 365 mm TL specimen taken from a fish market at Manabí, Ecuador, are the third and fourth species known for the genus and family. M. prolixus differs from the East Atlantic M. compressus Günther and the western North Pacific M. gracilis Castle in being much more slender and more elongate, in having a longer snout and more lateral line pores, and more preanal, precaudal and total vertebrae. M. nigrodentatus is somewhat like M. compressus in its robust body, short snout and relatively few lateral line pores but differs from all species in having the lowest number of preanal, precaudal and total vertebrae and most notably, internally dark-pigmented teeth, a large slit-like branchial aperture and bright orange body coloration.