The smooth reed-like stem of this species resembles those of the Geonomas, and it is also remarkable for the large size of its fruit. It grows on the dry sandy soil of the Catinga forests of the Upper Rio Negro. It seems most nearly allied to _B. mitis_ of Martius. A fruit is represented on the Plate of the natural size, and a leaflet reduced one-fourth to show the peculiar form. [Illustration: Pl. XXXIII. W. Fitch lith. Ford & West Imp. BACTRIS TENUIS. Ht. 6 Ft. ] PLATE XXXIII. BACTRIS TENUIS, n. sp. Iú, _Lingoa Geral_. In this species the stem is not thicker than a goose quill, distinctly jointed and smooth. The leaves are terminal, four or five in number, and rather irregularly pinnate. The leaflets are elongate and acute, with produced points, four or five in number, on each side of the midrib, the terminal pair being the broadest. The petioles and their sheathing bases are covered with small, flat, black spines. The spadices grow from below the leaves and are very small and unbranched. The spathes are fusiform, erect, persistent and smooth. The fruit is small, globose, and of a red colour. This is one of the smallest of Palms, and in every part of its structure offers a striking contrast to the great _Mauritia_ and other giants of the family. While they possess huge columnar stems a hundred feet in height and two feet in diameter, this has but a slender stalk the thickness of a quill; and while their fruit bunches are the largest in the vegetable kingdom, the whole spadix of this species is smaller than a bunch of currants. It is allied to _B. cuspidata_ and to _B. fissifrons_ of Martius, but seems sufficiently distinct from either of them. It grows exposed to the sun in the sandy Catinga forests of the Upper Rio Negro. An entire spadix with fruit is represented on the Plate, of the natural size. [Illustration: Pl. XXXIV. W. Fitch lith. Ford & West Imp. BACTRIS SIMPLICIFRONS. Ht. 6 Ft. ] PLATE XXXIV. BACTRIS SIMPLICIFRONS, _Martius_. Iú, _Lingoa Geral_. The stem of this little palm resembles in size and appearance that of _B. tenuis_. The leaves are five or six in number, terminal, and consist of a single broad bifid leaflet, or more properly a pair of opposite terminal leaflets. The petioles and their sheathing bases are thickly set with spines. The spadices grow from below the leaves; they are unbranched and bend downwards, and the spathes are elongate, small, erect or horizontal, smooth and persistent. This pretty little species seems identical with one described by Martius under the name of _Bactris simplicifrons_. It is not uncommon in the dry Catinga forests of the Upper Rio Negro. BACTRIS MARAJA, _Martius_. Marajá, _Lingoa Geral_.