brous, glabrous, slender but stout in relation to the plant. 
Stems minute, up to 5 mm. tall, concealed by one to 
three scarious tubular imbricating sheaths. Leaf solitary, 
linear-elliptic to oblanceolate-linear, subacute to rounded 
and minutely tridenticulate at the apex, cuneate-nar- 
rowed at the base, up to 1.7 em. long and 2.4 mm. wide, 
subcoriaceous, with the mid-nerve more or less conspic- 
uous. Scape filiform, more or less surpassing the leaf, 
with a single tubular closely clasping sheath near or be- 
low the middle, arising near the base of the stem, 1- to 
very rarely 4-flowered. Peduncle about 2.8 cm. or less 
tall. Flower small, membranaceous except the sepaline 
tails, somewhat bilabiate. Sepals connate at base. Dor- 
sal sepal about 5.8 mm. long, connate with the lateral 
sepals for about 1.1 mm., basal part of the free portion 
about 2 mm. long, suborbicular-ovate, 3-nerved, abruptly 
contracted into a fleshy linear-subclavate cauda which is 
about 3.7 mm. long. Lateral sepals about 7.2 mm. long, 
connate for 2.8 mm.; each free part ovate-lanceolate, 
3-nerved, abruptly contracted into a fleshy linear cauda 
which is about 2.8 mm. long. Petals much smaller, lan- 
ceolate, acute, very unequally tridentate at the apex, 2 
mm. long, about 0.9 mm. wide near the middle, 1-nerved. 
Lip minutely unguiculate, oblong-lanceolate, 2. mm. 
long, about 0.75 mm. wide, rounded at the apex, 3- 
nerved, with two intramarginal fleshy keels above the 
lateral nerves of the basal half, the keels extended into 
minute auricles. Column short, stout, terminating in a 
dentate wing. 
Masdevallia tenuissima is allied to M.exvigua A. & S., 
and the very similar M. pygmaea Kriinzl., but differs 
from both in having elongate scapes, not echinate ovary, 
and dissimilar petals and lip. 
Panama, Province of Coclé, mountains beyond La Pintada. At 
400-600 meters altitude. February 17, 1935. dA. 4. Hunter & P. H. 
[112 ] 
