described them as different) pronounced that they were distinct species; a conclusion in conformity with the trifling difference of habit and geographical range, of which he was not at the time aware. 3. MIMUS THENCA. _G. R. Gray._ Turdus Thenca. _Mol._ Orpheus Thenca. _D’Orb._ Voy. de l’Amer. Mer. Orn. p. 209, pl. f. 3. This species seems to be confined to the coast of the Pacific, west of the Cordillera, where it replaces the _M. Orpheus_, and _M. Patagonicus_ of the Atlantic side of the continent. Its southern limit is the neighbourhood of Concepcion, (lat. 37° S.) where the country changes from thick forests to an open land. The Thenca, (which is the name of this species, in the language of the Aboriginal Indians,) is common in central and northern Chile, and is likewise found (I believe the same species) near Lima, (lat. 12°) on the coast of Peru. The habits of the Thenca are similar, as far as I could perceive, to those of the _M. Patagonicus_. I observed many individuals, which had their heads stained yellow from the pollen of some flower, into which they bury their heads, probably for the sake of the small beetles concealed there. Molina describes the nest of the Thenca, as having a long passage, but I was assured by the country people, that this nest belonged to the _Synallaxis ægithaloides_, and that the Thenca makes a simple nest, built externally of small prickly branches of the mimosa. 4. MIMUS TRIFASCIATUS. _G. R. Gray._ PLATE XVI. Orpheus trifasciatus. _Gould_, in Proc. of Zool. Soc. Part v. 1837, p. 27. _M. vertice, nuchâ, et dorso nigrescentibus; uropygio rufo pallidè lavato; alis nigrescentibus, tectricibus notâ albescente terminali fascias tres transversas facientibus; rectricibus caudæ duabus intermediis nigrescentibus, reliquis ad apicem pallidioribus; plumis auricularibus, strigâ superciliari, gulâ, et corpore subtùs albis, lateribus notis guttisque fuscis ornatis; rostro pedibusque nigris._ Long. tot. 10⅝ unc.; _rost._ 1⅜; _alæ_, 5; _caudæ_, 5½; _tarsi_, 1¾. The vertex, nape of the neck and the back, blackish; with the lower part of the back tinged with pale rufous; the wings blackish, with the tips of the wing coverts white, forming three transverse bands; the tail with the two intermediate feathers black, with the tips of the others much paler; the auricular feathers with a streak above the eyes, throat, and beneath the abdomen white; the flanks ornamented with fuscous marks and spots. Habitat, Charles Island, Galapagos Archipelago. (_October_). 5. MIMUS MELANOTIS. _G. R. Gray._ PLATE XVII. Orpheus melanotis, _Gould_, in Proc. of Zool. Soc. Part v. 1837, p. 27.