formerly attributed to this concept makes advisable the 
following redescription: 
Plant small, caespitose, up to 10 cm. high. Pseudo- 
bulbs complanate, ovoid to ellipsoid, about 1 cm. high, 
unifoliate, finely rugose in the dried specimen, clothed 
at the base with two pairs of sheaths, the upper being 
larger and leaf-bearing. Leaves with more or less con- 
spicuous petioles, up to 9.4 em. long; lamina elliptic to 
oblong, acute, cuneate below, up to 8 cm. long and 1.4 
cm. wide. Inflorescence subequaling or surpassing the 
leaves, spreading, 1-flowered ; peduncle mostly concealed 
by several loose, tubular sheaths of which the lower are 
successively smaller and imbricated. Flower large for the 
plant, membranaceous and nervose. Dorsal sepal linear- 
lanceolate or linear-triangular, long-acuminate, 1.8—2.6 
cm. long, 4-4.6 mm. wide across the concave base. Lat- 
eral sepals linear-triangular to narrowly triangular- 
lanceolate, oblique, slightly longer and noticeably broad- 
er than the dorsal sepal, forming a conspicuous mentum 
at the base. Petals similar to the lateral sepals, but mark- 
edly smaller. Lip erect, parallel to the column and lightly 
recurved in natural position, more or less sharply 3-lobed 
in the middle, elliptic-lanceolate to ovate-lanceolate in 
outline when expanded, about 1.5—1.8 cm. long, 5-9 mm. 
wide; mid-lobe triangular-lanceolate to ovate-lanceolate, 
dorsally keeled and mucronate at the apex; disc with a 
more or less pronounced median, longitudinal callus. 
Column short and stout, 4-5 mm. high at the back, ex- 
tended into a slightly longer foot. 
Venezue.a: State of Bolivar, Ptari-tepui, on densely forested, steep, 
south-facing slopes overlying sandstone, between ““Cave Rock’’ and 
the base of high sandstone bluffs, 2100-2285 meters altitude, flower 
brown and yellow, October 30, 1944, Julian A. Steyermark 59359. 
Peru: Cuzco; Province of Paucartambo, Santa Isabel to Asuncion, 
epiphyte at 1800 meters altitude, flower wine-red, January 4, 1946, 
C. Vargas 5536. 
[ 56 | 
