A medium-sized (53–108 cm total length) snake with a distinctive sequence of red, black, and white rings (tricolor dyads: Savage and Slowinski 1990; these are similar, but yet different from the triads of Zweifel 1952b) in which relatively narrow white rings are always bordered by black rings, and red coloration, which can occur as rings or bands, borders alternate black rings (Zweifel 1952b; pers. observ.). Occasional aberrant patterns can be found in which rings are lacking (see Figure 2 in McGurty 1988). The number of tricolor dyads on the body (except the tail) ranges from 27 to 38, and between 15% and 100% of the red rings between body dyads are complete (Zweifel 1952b). The snout is jet black and the iris is very dark brown (B. McGurty, pers. comm.).
