TROPICAL AMERICAN ORCHIDS 
out, anterior margin rounded and denticulate, 3-nerved, with 
the apices of the nerves pyriform-dilated, centre of the lip and 
margins at the middle much thickened. Column very small, 
3 mm. long, narrowly margined with a lightly trilobulate 
wing, extending into a stout subequally long foot which 
forms a mentum with the lateral sepals. 
Pleurothallis crassilahia seems to be allied to P. Cogn- 
iauxiana Schltr., but differs markedly in the shape of the 
petals and lip. It is very similar to the Brazilian P. bicari- 
nata Lindk, but has a creeping rhizome, inflorescence about 
half as long as the leaf, and deeply lacerate-serrate petals. 
The description of the flower was mostly taken from an 
alcoholized flower, numbered 526, and sent to complete the 
numbers cited below. 
Costa Rica, Alto de La Estrella, Cartago, C. H. Lan- 
kester 807, March 26, 1924. Flowers half open, orange 
yellow, plants frequently occur in large colonies, on moss- 
covered trees, common south of Cartago. (Type in Herb. 
Ames No. 28722.): Tobosi, C. H. Lankester 535. 5000 feet 
altitude. “FI. orange chrome.” 
Pleurothallis decipiens A.& S. sp. nov. Herba medio- 
cris, rhizomate repenti. Caules secundarii elongati, graciles, 
monophylli. Folium lineari- vel lanceolato-oblongum, rigide 
coriaceum. Racemi fasciculati, perbreves, pauciflori. Flores 
parvi. Sepala lateralia in laminam bidentatam connata, 
extus alte carinata. Sepalum dorsale oblongo-lanceolatum, 
tertia parte apicali valde incrassata. Petala minuta, cuneato- 
spathulata. Labellum simplex, expansum subpandurato- 
quadratum. 
Plant medium-sized, about 22.5 cm. tall. Rhizome 
creeping, slender, entirely concealed by closely wrapped 
sheaths, somewhat branched. Roots fibrous, filiform, flex- 
uous, glabrous, long, somewhat branched. Secondary stems 
slender, elongate, 6.5-12.1 cm. tall, approximate to 2.2 cm. 
apart, about 1 mm. in diameter, sulcate-angulate in the dried 
state, enveloped below by about two close tubular evanes¬ 
cent sheaths. Leaf solitary at the summit of each stem, 
erect, linear-oblong or lanceolate-oblong, about 10-11 cm. 
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