PSEUDOBULBS _oblong, very much compressed and very sharp at the edges, 1½ to 2 inches long_. LEAVES _one (rarely if ever two) on each pseudobulb and broadly-oblong acute shorter than the scape_. SCAPE _and_ RACEME _sheathed at intervals with long keel-shaped membranaceous_ BRACTS, _few or many flowered, simple or (more rarely) branched, from one to two feet high_. SEPALS _and_ PETALS _nearly equal, linear-lanceolate, extremely acuminate, an inch or more long, greenish-yellow richly blotched with brown_. LIP _shorter than the sepals heart-shaped, with a very acuminate slightly recurved apex, white with dark brown spots and a purplish 2-lobed callus at the base_. COLUMN _pubescent, club-shaped, almost wingless_. Though scarcely to be classed among the more attractive species, _O. cordatum_ is occasionally seen at our Shows with branching scapes 2 feet high and flowers much more richly coloured than those in the Plate. It is found both in Mexico and Guatemala (whence plants were sent to me by my lamented friend Skinner), but always at high elevations. It flowers in the early summer without any special treatment, except that it is perhaps more impatient of water than some of its congeners. Plate XXVI [Illustration: Odontoglossum angustatum.] PLATE XXVI. ODONTOGLOSSUM ANGUSTATUM. NARROW-PETALLED ODONTOGLOSSUM. O. (ISANTHIUM) pseudobulbis ovato-oblongis compressis, foliis longis lato-lanceolatis erectis acutis paniculâ ramosâ elatâ brevioribus, bracteis carinatis acutis ovario multò brevioribus, sepalis petalisque subæqualibus undulatis unguiculatis, labello ovato-lanceolato acuminato reflexo, cristæ lamellis lateralibus membranaceis trifidis, digitis anterioribus majoribus, callo obtuso interposito, columnâ apterâ. ODONTOGLOSSUM ANGUSTATUM, _Lindl. in Bot. Reg._ _sub_ t. 1992, _Folia Orchid._, 48; _Rchb. fil._; _Walper's Annales_, vi. p. 841. Habitat in PERU, (alt. 8000 ft.,) _Hall_, _Hartweg_, _Linden_. DESCRIPTION. _A very stately plant._ PSEUDOBULBS _ovate-oblong compressed, 2 or 3 inches long, 1 (or ? 2) leaved_. LEAVES _one to one and a half feet long, linear-lanceolate acute, shorter than the upright branching zigzag many-flowered_ PANICLES. BRACTS _keeled, acute, much shorter than the ovaries_. SEPALS _and_ PETALS _nearly equal, unguiculate, acuminate, undulated, white with beautiful purple spots on their lower portions_. LIP _white, or nearly so, shorter than the petals, ovate-lanceolate, the apex acuminate and exceedingly recurved, having at its sides two membranous lamellæ, divided into three unequal parts, those in front the larger and projecting forwards like horns or fingers with a blunt callus lying between them_. COLUMN _not half the length of the lip, and destitute of wings_.