gutta, not guttus (invariable Latin substantive; meaning: drop or droplet). The question of separation between P. gutta (= pacificus = vinctus auct., non Say), a supposed Oriental and Pacific species, and P. vinctus Say, a species inhabiting the New World, is not yet solved (see J.A. Slater, 1964a: 1135). So the synonymies proposed above are probably not definite. The terms Misidentification? point out the ambiguities.