+Picus mixtus+, _Scl. et Salv. Nomencl._ p. 99; _Durnford, Ibis_, 1878, p. 62 (Buenos Ayres); _White, P. Z. S._ 1882, p. 617 (Catamarca); _Barrows, Auk_, 1884, p. 25 (Entrerios); _Withington, Ibis_, 1888, p. 467 (Lomas de Zamora). _Description._--Above black, with regular white cross bars; head black, with narrow yellowish shaft-spots; a large patch behind the ear on each side of the neck white; feathers of the nape slightly pointed with rosy red: beneath white, with longitudinal black stripes; under surface of wings white, with black cross bars: whole length 6·0 inches, wing 3·5, tail 2·2. _Female_ similar, but head uniform black, and no red on the nape. _Hab._ South Brazil and Argentina. In the district of Buenos Ayres this little Woodpecker, the smallest of the Argentine species of the family, is usually called _Come-palo_ (Wood-eater) in the vernacular. It has all the habits characteristic of the true Woodpeckers, inhabiting the woods and perching vertically on the trees, where it is heard vigorously striking the bark to dislodge the lurking insects with its sharp beak. When disturbed it flits away with a shrill querulous cry, passing to the nearest tree with a rapid undulating flight, and conceals itself by running round the bole to the opposite side. It excavates a straight hole in a rotten or decaying branch to breed in, and a common species of _Synallaxis_ (_Leptasthenura ægithaloides_) frequently makes use of its forsaken breeding-holes. The entire plumage in both sexes is very dark, nearly black, densely and evenly marked with oblong white spots. The loose feathers of the crown are black tipped with scarlet, but in the female the one spot of bright colour is scarcely if at all perceptible. White met with this Woodpecker near Cordova and in Catamarca, and Mr. Barrows in Entrerios, where, however, though resident, it does not appear to be common. 252. PICUS CACTORUM, d'Orb. et Lafr. (CACTUS WOODPECKER.) +Picus cactorum+, _Scl. et Salv. Nomencl._ p. 99; _Salvin, Ibis_, 1880, p. 361 (Salta); _White, P. Z. S._ 1882, p. 617 (Catamarca); _Barrows, Auk_, 1884, p. 25 (Gualeguaychú). +Dendrobates cactorum+, _Burm. La-Plata Reise_, ii. p. 445 (Catamarca). _Description._--Above black; large blotch on the front and another on the nape dull white; small coronal spot scarlet; wings and tail black, with white cross bands; rump white, spotted with black: beneath buffy white, throat strongly tinged with orange; bill and feet black: whole length 6·8 inches, wing 4·1, tail 2·3. _Female_ similar, but without the red spot on the crown. _Hab._ Bolivia and Northern Argentina.