Subspecies and Distribution. S. m. mystax Spix, 1823 — S of the Amazon River in WBrazil (W of the Rio Jurua) and NE Peru, as far W as the E banks of the middle and lower Rio Tapiche and the lower Rio Ucayali, further S it extends W as far as the Rio Ucayali, crossing the Rio Tapiche at c.6° 40' S, the S limit is marked by the rios Urubamba and Inuya. S. m. pileatus 1. Geoffroy Saint-Hilaire & Deville, 1848 — Brazilian Amazon, W of the Rio Purus, S at least as far as the Rio Pauini or Rio Mamornia. S. m. pluto Lonnberg, 1926 — Brazilian Amazon, from the W (left) bank of the Rio Purus, N of the Rio Tapaua, as far W as the Rio Coart. in Callitrichiade

Subspecies and Distribution. S. m. mystax Spix, 1823 — S of the Amazon River in WBrazil (W of the Rio Jurua) and NE Peru, as far W as the E banks of the middle and lower Rio Tapiche and the lower Rio Ucayali, further S it extends W as far as the Rio Ucayali, crossing the Rio Tapiche at c.6° 40' S, the S limit is marked by the rios Urubamba and Inuya. S. m. pileatus 1. Geoffroy Saint-Hilaire & Deville, 1848 — Brazilian Amazon, W of the Rio Purus, S at least as far as the Rio Pauini or Rio Mamornia. S. m. pluto Lonnberg, 1926 — Brazilian Amazon, from the W (left) bank of the Rio Purus, N of the Rio Tapaua, as far W as the Rio Coart.